The heterogeneity of tumor cells is the basis of tumor formation, so tumor is a kind of cellular disease. Compared with normal cells, tumor cells have abnormal structure, function and metabolism, and also have supernormal proliferation ability. In-depth study of the life cycle, invasion, apoptosis and metabolic mechanisms of tumor cells will help people to better understand the process of tumorigenesis. It also plays an important role in exploring tumor immunotherapy and immune escape, tumor targeted therapy, tumor drug resistance related research and tumor microenvironment. Tumor cell biology technology is the main method to study these biological problems, and it is also the main method used in basic research in recent years.