Abstract
C3a is a key active factor in the complement system, capable of participating in various physiological and pathological processes by binding to its C3a receptor (C3aR). The C3a-C3aR pathway not only plays an important role in immune regulation but is also closely related to the occurrence and development of various inflammatory diseases, cardiovascular diseases, autoimmune diseases, and tumors. In recent years, research on the specific mechanisms of action of C3a-C3aR in different diseases has gradually deepened. This article aims to review the basic functions of the C3a-C3aR pathway, with a focus on summarizing the latest research advances in kidney diseases, cardiovascular diseases, neurodegenerative diseases, autoimmune diseases, and tumors, and to explore its prospects as a potential therapeutic target.