Unlike normal cells, cancer cells have three major characteristics: infinite growth, transformation and metastasis, and are therefore difficult to destroy. Unlike normal cells, cancer cells have three characteristics: infinite growth, transformation and metastasis, and are therefore difficult to destroy. Cancer cells are derived from “mutated” normal cells and take many years to grow into tumors. In the process of cell differentiation, “renegade” cells are detached from the normal course and set their own proliferation rate, accumulating to more than 1 billion before we notice them. The proliferation rate of cancer cells is calculated by multiplication time, one becomes two, two becomes four, and so on. For example, the average multiplication time of stomach, intestine, liver, pancreatic and esophageal cancers is 31 days; breast cancer multiplication time is more than 40 days. As cancer cells keep multiplying, the more advanced the cancer is, the faster it develops. Nowadays, medical doctors believe that all people have proto-oncogenes in their bodies, but not all people have cancer cells in their bodies. The proto-oncogene is responsible for cell division and proliferation, and is needed for human growth. In order to “control” it, there are also oncogenes in the human body. Normally, the proto-oncogene and the oncogene maintain a balance, but under the effect of carcinogenic factors, the proto-oncogene becomes more powerful, while the oncogene becomes weaker. Therefore, cancer-causing factors are the “keys” to initiate the growth of cancer cells, mainly including mental factors, genetic factors, lifestyle, certain chemical substances, etc. Multiple “keys” are used together to start the “cancer program”; the more “keys” there are, the greater the chance of starting it. We have not been able to decipher all the “keys” yet, so we have not been able to overcome cancer yet. A lung cancer cell dividing