自噬是一个亚细胞膜动态形态学变化的过程，可导致细胞内蛋白质和细胞器降解。自噬与人类的多种疾病密切相关，尤其是在癌症启动和发展中起着关键作用。一方面，自噬和由此产生的细胞死亡程序可以抑制肿瘤的发生和发展；另一方面，自噬是一种自我保护机制，可在癌症进展阶段保证肿瘤细胞生存，防止营养物质匮乏、电离辐射、化疗等对肿瘤细胞的破坏。该文就自噬抑制和促进肿瘤的机制进行综述。

Autophagy is a process in which subcellular membranes undergo dynamic morphological changes that lead to the degradation of cellular proteins and cytoplasmic organelles. Autophagy is closely associated with many diseases, and plays a role in the development of cancer. On one hand, autophagy and cell death process may suppress the development of tumours; on the other hand, autophagy is a self-defence mechanism, which may protect the tumour cells from injury caused by nutrition deficiency, ionizing radiation and chemotherapy during tumour development. In this review the mechanisms that link autophagy to tumour suppression and promotion are discussed.