癌症是以细胞不协调地生长为特征的细胞增生性疾病。细胞的增生是通过细胞周期有规律地进行的，即使是癌细胞也仍旧通过细胞周期而增生，只是细胞周期的调节在癌细胞中发生了改变，故癌症也可以被看作为细胞周期的疾病。要深入地了解癌生成的机制有必要对细胞周期的调节及其在 Cancer is a cell proliferative disease characterized by the uncoordinated growth of cells. The proliferation of cells is carried out regularly through the cell cycle. Even cancer cells still proliferate through the cell cycle, but the regulation of the cell cycle has changed in cancer cells, so cancer can also be seen as a disease of the cell cycle. To understand the mechanism of cancer formation it is necessary to regulate the cell cycle and