C4b 结合蛋白 (C4BP) 是一种液相补体抑制剂，可防止经典补体途径和凝集素补体途径不受控制的激活。作为补体抑制剂，C4BP 还会促进细胞凋亡，并被微生物和肿瘤劫持以逃避补体。尽管最初的特征是其在补体抑制中的作用，但人们逐渐认识到 C4BP 以补体独立的方式发挥作用，以促进细胞存活、防止自身免疫损伤并调节微生物病原体的毒力。在这篇简短的综述中，我们总结了人类 C4BP 的结构和功能，特别关注超出 C4BP 在补体抑制中的典型作用的活动。版权所有 © 2023 美国免疫学家协会，Inc.。

C4b-binding protein (C4BP) is a fluid-phase complement inhibitor that prevents uncontrolled activation of the classical and lectin complement pathways. As a complement inhibitor, C4BP also promotes apoptotic cell death and is hijacked by microbes and tumors for complement evasion. Although initially characterized for its role in complement inhibition, there is an emerging recognition that C4BP functions in a complement-independent manner to promote cell survival, protect against autoimmune damage, and modulate the virulence of microbial pathogens. In this Brief Review, we summarize the structure and functions of human C4BP, with a special focus on activities that extend beyond the canonical role of C4BP in complement inhibition.Copyright © 2023 by The American Association of Immunologists, Inc.