科学家们通过研究,发现每个人身上都存在着癌基因。至今,人类共发现不同的癌基因有20多种。正常情况下,细胞内的癌基因并不闹事,当外环境和内环境发生改变时,尤其是种种致癌因素的刺激,便会激活癌基因,使细胞发生突变无限增生而成为癌细胞。科学家们发现,激活癌细胞基因的化学物质有1000多种,如香烟、烹调时油烟中的有害物质可激活肺癌基因;黄曲霉毒素、乙肝病毒等是肝癌基因的激活因子;亚硝基化 Through research, scientists found that there are oncogenes in everybody. To date, humans have discovered more than 20 different oncogenes. Under normal circumstances, the intracellular oncogene does not cause troubles. When the external environment and internal environment change, especially the stimulation of various carcinogenic factors, it activates the oncogene and causes the cells to undergo infinite mutation and become cancerous cells. Scientists have discovered that there are more than 1,000 kinds of chemical substances that activate cancer cell genes, such as cigarettes, harmful substances in cooking fumes can activate lung cancer genes; aflatoxins, hepatitis B virus, etc. are activation factors of liver cancer genes; nitrosation