Apoptosis, also named programmed cell death, is a highly conserved physiological mechanism. Apoptosis plays crucial roles in many life processes, such as tissue development, organ formation, homeostasis maintenance, resistance against external aggression, and immune responses. Apoptosis is regulated by many genes, among which Apoptosis Inhibitor-5 (API5) is an effective inhibitor, though the structure of API5 is completely different from the other known Inhibitors of Apoptosis Proteins (IAPs). Due to its high expression in many types of tumors, API5 has received extensive attention, and may be an effective target for cancer treatment. In order to comprehensively and systematically understand the biological roles of API5, we summarized the evolution and structure of API5 and its roles in anti-apoptosis in this review.

细胞凋亡，也称为程序性细胞死亡，是一种高度保守的生理机制。细胞凋亡在许多生命过程中起着至关重要的作用，例如组织发育、器官形成、体内平衡维持、抵抗外部攻击和免疫反应。细胞凋亡受多种基因调控，其中Apoptosis Inhibitor-5 (API5) 是一种有效的抑制剂，尽管API5 的结构与其他已知的凋亡蛋白抑制剂(IAPs) 完全不同。由于在多种肿瘤中的高表达，API5受到了广泛关注，有望成为治疗癌症的有效靶点。为了全面系统地了解API5的生物学作用，我们在本综述中总结了API5的进化和结构及其在抗细胞凋亡中的作用。