The human immune system helps to protect the body against illness and infection caused by bacteria, viruses, fungi, and parasites.  This process is achieved by a collection of reactions and responses made by the body to damage these infected cells. It is also called immune responses.
This immune system is very crucial in cancer patients to help fight cancer, it dictates this cancer as abnormal and destroys it, but this is not enough to rid of cancer altogether.  In most cases, cancer will weaken this immune system because it will spread into the bone marrow that produces blood cells that fights against infections and cause the bone marrow to decrease in its blood cell production. 
When this immune system is unable to recognize these cells as abnormal, cellular growth will occur, causing uncontrolled growth and division of cells, that will, in turn, lead to cancer. 
Cancer has been a serious and sensitive talk for both patients and doctors. Being diagnosed with cancer is frightening and tormenting, but due to the latest treatment method, recovering from this disease is increasingly possible. Living with cancer often brings an initial psychological crisis, but surprisingly it does not only affect you but your family and others close to you. 
Cancers, especially genetic cancer can’t be prevented, so it is essential to be proactive about your health. If you’re diagnosed with cancer, some individual lifestyles that will help improve your cancer care, which includes managing stress. Reducing your stress level can help you to maintain physical and mental stress; you can use relaxation techniques such as meditation and yoga. Getting enough sleep is also crucial for patients living with cancer; this will help improve their health, mood, and coping ability. Also, it is best the limit their exposure to toxins that can increase one’s risk of being exposed to other deadly diseases. 
A healthy feeding habit is critically important and can help manage cancer side effects, improve health, and quick recovery. Some tips to help you develop a good and healthy feeding diet include:

• Consuming assorted types of vegetables in all your meals. Vegetables are essential and should not just be a side dish but the centerpiece of your meal.
• Consuming foods rich in fiber like grains, beans, peas, nuts, and seeds.
• Consuming less red meat, like pork, lamb, goat, and bison.
• The presence of probiotic and prebiotic foods helps to support a healthy gut. Probiotic foods include yogurt or other fermented vegetables, and prebiotic foods include raw or cooked onions, dandelion greens, and legumes.
• Avoid processed and canned foods
• Avoid foods high in calories and low in nutrients like fruit-flavored drinks, sodas, candies, and sweets.
• Lastly, cut down on the excessive intake of alcohol.

Some other routines can help improve cancer care like regular exercise. Regular exercise helps to control fatigue, muscle tension, and anxiety in those with cancer, and it is essential, especially during and after cancer treatment, so keep fit and avoid adding unnecessary weight.
CANCER TREATMENT
There are many cancer treatment options for different types of cancers. Cancer treatments depend on the type and how to advance it is. Some patients with cancer will only have one treatment option, while others will end up with a combination of more that one treatments technique  depending on the type and stage of cancer. 
Curing cancer is one of the significant challenges of the 21st century. However, few advances to tame the immune system are getting closer to a future where cancer can be a curable disease. 
Although cancer treatment is dependent on the stage and type, we need a wide range of therapies that work on cellular level like NK cell and stem cell therapies, wide enough to cover the whole spectrum of cancer. Cancer therapies involving the immune system is believed to be a milestone for cancer treatment advances, and the development of multiple immune cells as a therapeutic tool.
Our knowledge of cancer has dramatically improved in recent years. And it seems increasingly evident that there has been a surge of new technologies, and these technologies could make a great impact on the way we treat cancer, taking us closer to finally curing this deadly disease. 
One of these promising cancer treatment advances is the natural killer (NK) cell-based immunotherapy.
NK CELLS
Natural killer cells have emerged as the newest promising therapeutic approach to cancer. Our understanding of the biological processes that take place in cancer is increasing rapidly, leading to this new type of targeted treatment and therapeutic approach.  It is hard to overstate the possible importance of NK cells in the future of cancer. Modern researches have shown that NK cells are a type of treatment that stimulates a persons’ immune system to fight cancer, and this may give room for a greater number of chances to beat cancer for good. NK cells are also known for their ability to target cancer stem cells making these cancer stem cells visible to the immune system.
NK cells was first identified in the 1970s as a unique lymphocyte subset that can recognize and kill abnormal cells without prior sensitization of specific tumor antigen, thus preventing the growth of many cancers. During the late 1980s, something was observed, and this was that NK cells could destroy a lymphoma cell line that had lost MHC class I surface molecules while the original MHC class I+ cells were resistant to lysis, which led to the formation of the “missing self-hypothesis” which states that NK cells can sense the absence of “self” MHC class-I molecule on target cells.  In recent years, the hypothesis was confirmed by the inhibitory and activating NK cell receptors. 
This discovery indicates that autologous cells are not killed by NK cells, thanks to an appropriate expression of all self-HLA alleles, do not kill an autologous cell. In contrast, a wide spec of cancer types can be killed due to the loss of HLA molecules and to the expression/overexpression of ligands for NK cell activating receptors.   
Now, this is how NK therapy works
NK cells firsts recognize the tumor cells via stress or danger signals from their sensors. 
Then, the Activated NK cells directly decimate the target tumor cells through at least four mechanisms. These mechanisms are cytoplasmic granule release, death receptor-induced apoptosis, effector molecule production, or ADCC. 
Furthermore, NK cells act as regulatory cells when reciprocally interact with DCs to improve their antigen uptake and presentation. This action helps in facilitating the generation of antigen-specific CTL responses that is vital in dictating foreign invasion and tumor cells. 
Also, by producing cytokines such as IFN-γ, activated NK cells induce CD8+ T cells to become CTLs. Activated NK cells can also help in the differentiation of CD4+ T cells toward a Th1 response and promote CTL differentiation. Cytokines produced by NK cells might even have the unique ability to regulate antitumor cells, making them more proactive. 
Accordingly, The cytokine gene transfer approach induces NK cell proliferation, and this increases survival capacity. Further enhancing their activation and also making them more potent in malignant cell multiplication dictation. 
The NK cell scientist has assured that by using NK cell lines, modifying genes such as IL-2, IL-12, IL-15, and stem cell factor (SCF). They have been demonstrated the ability of the NK to restore their cytotoxic capacity as well as increase their proliferative rate, survival ability, and in vivo antitumor activity. However, the specificity of NK cells is still limited, and studies are even passing through phases. The approach focuses on retargeting NK cells to tumor cells by gene transfer of chimeric tumor-antigen specific receptors. 
NK therapy is promising research; it raises the prospect of “one-end-solution” to many different types of cancers across the Globe. If the studies and experiments work out pretty well, the NK cells will be able to increase the activity of CD4+, CD19, and other important disease-fighting cells of the body. 
There is no doubt that this an unimaginable feat, both in advancing our basic knowledge about regenerative medicine and for the possibility of future cancer treatment advances.