The process of transforming normal cells into cancer cells is called ‘carcinogenesis’ or ‘malignant transformation’. The causes and processes of cancer are not yet fully understood. Generally speaking, the transformation of normal human cells into cancer cells is a complex process, which takes quite a long time, usually 10 years or decades, from quantitative to qualitative changes. Most scientists believe that cell cancer is the result of ‘genetic mutation’ or “genetic dysfunction”. In tumor research, it has been found that there is a set of genes that can cause cellular cancer naturally in human cells – ‘oncogenes’. Under normal circumstances, oncogenes are not harmful to human body, but play an important role in cell growth and differentiation. Therefore, although everyone has oncogenes, not everyone gets cancer. Only when normal cells are repeatedly affected by external carcinogenic factors, the oncogene in a quiescent state will be activated and the gene structure will be mutated or the gene expression will be out of control, so that the normal biological traits of the cells will be changed and the dynamic balance of normal cell metabolism will be disrupted, and cancer cells will be produced. Recently, scientists have been able to isolate oncogenes from the cells of more than 20 tumor patients, such as bladder cancer, lung cancer and colon cancer. Therefore, it is believed that oncogene activation is an important cause of cellular carcinogenesis.