某种组织对癌的敏感性和其增殖能力有关,人类许多肿瘤都来源于持续再生的组织,不具有自我更新能力或更新能力很差的组织,如人的神经原很少患癌.当组织积极进行自我更新时对致癌物的敏感性也增高.在生命过程中,细胞分化和增殖最活跃阶段是在子宫内的胚胎时期,因之人们估计胚胎时期很易生恶性肿瘤。但是瑞典Karolinska 研究所的Lena Ei-nhorn 根据文献综述提出在胚胎时期癌的发展受到抑制的观点.虽然细胞分化和增殖在胚胎时期最旺盛,但新生儿或初生动物很少患癌,癌症很少成为初生儿或新生动物死亡或自发流产的原因.研究工作者用辐射、接种化学致癌物等方法处理动物的早期胚胎企图诱发肿瘤一直末获成功,甚至对接受致癌物或接受照射的动物进行整个生命过程的观察也未发现与末经处 The sensitivity of certain tissues to cancer is related to their ability to proliferate. Many tumors in humans are derived from tissues that are continuously regenerated. Tissues that do not have self-renewal ability or poor renewability, such as human neurons, rarely develop cancer. The susceptibility to carcinogens is also increased during active self-renewal. In the process of life, the most active stage of cell differentiation and proliferation is in the embryonic period of the uterus, and it is estimated that embryos are prone to develop malignant tumors. However, Lena Ei-nhorn of the Karolinska Institute in Sweden proposed a viewpoint that the development of embryonic cancer is inhibited based on literature review. Although cell differentiation and proliferation are most prosperous during the embryonic period, neonatal or neonatal animals rarely have cancer, and cancer is rare. Become the cause of death or spontaneous abortion of newborn or newborn animals. Researchers used radiation, inoculation of chemical carcinogens and other methods to treat the animals’ early embryos to induce tumors have been successful, even for animals that received carcinogens or received irradiation. Observations of life processes have not been found at the end