Membrane cofactor protein (MCP; CD46), a ubiquitously expressed complement regulatory protein, serves as a cofactor for serine protease factor I to cleave and inactivate C3b and C4b deposited on host cells. However, CD46 also plays roles in human reproduction, autophagy, modulating T cell activation and effector functions and is a member of the newly identified intracellular complement system (complosome). CD46 also is a receptor for 11 pathogens (‘pathogen magnet’). While CD46 deficiencies contribute to inflammatory disorders, its overexpression in cancers and role as a receptor for some adenoviruses has led to its targeting by oncolytic agents and adenoviral-based therapeutic vectors, including coronavirus disease of 2019 (COVID-19) vaccines. This review focuses on recent advances in identifying disease-causing CD46 variants and its pathogen connections.

膜辅因子蛋白（MCP；CD46）是一种普遍表达的补体调节蛋白，作为丝氨酸蛋白酶因子 I 的辅因子来裂解和灭活沉积在宿主细胞上的 C3b 和 C4b。然而，CD46 还在人类生殖、自噬、调节 T 细胞激活和效应功能中发挥作用，并且是新发现的细胞内补体系统（复合体）的成员。 CD46 也是 11 种病原体（“病原体磁铁”）的受体。虽然 CD46 缺陷会导致炎症性疾病，但它在癌症中的过度表达以及作为某些腺病毒受体的作用导致其成为溶瘤药物和基于腺病毒的治疗载体的靶标，包括 2019 年冠状病毒病 (COVID-19) 疫苗。本综述重点关注鉴定致病 CD46 变异及其病原体联系的最新进展。