肿瘤是在某些致瘤因素作用下,机体对部分细胞正常生长的控制机能发生障碍,该部细胞发生质的变化,而出现异常增生,形成的肿物。因此,肿瘤细胞是由正常细胞转化而来。为什么一个正常细胞变成了癌细胞呢?概括近年来的研究资料,对此可有两种解释:(1)认为细胞的基因发生了突变,即体细胞突变学说;(2)认为基因的结构不一定改变,可能是由于基因调节发生了错 Tumor is under the action of some tumorigenic factors, the body of some cells to control the normal growth of obstacles, the Department of cells undergo a qualitative change, and abnormal proliferation, the formation of the tumor. Therefore, tumor cells are transformed from normal cells. Why a normal cell into a cancer cell? Summarize the research data in recent years, there are two explanations for this: (1) that the cell gene mutation occurred, somatic mutation theory; (2) that the gene structure Not necessarily changed, probably due to a genetic mismatch