C5

C5, or complement component 5, is alias C5α, C5b, etc. It is part of the human complement system, produced by liver cells, and is a serum protein.The mechanism of action of C5 is primarily activated through the complement cascade reaction.C5 can be cleaved into two fragments, C5a and C5b, by either C4b2a (classical pathway and the lectin pathway) or C3bBb3b (the bypass pathway).C5a is a small molecule peptide with potent inflammatory activity that attracts and activates a variety of immune cells, such as neutrophils and monocytes, while C5b initiates the formation of membrane attack complexes (MACs), leading to the lysis of foreign cells.C5 has a wide range of biological significance, acting as a bridge between natural and acquired immunity.C5 activation is involved in important processes such as the clearance of pathogens and damaged cells, the modulation of inflammatory responses, and the promotion of chemotaxis and activation of immune cells The C5a-C5aR1 signaling pathway plays a role in a variety of inflammatory diseases, including the development of tumors such as colorectal cancer, and promotes tumorigenesis and progression by affecting the immune microenvironment and intracellular signaling.Abnormal activation of C5 has been closely associated with the development of a variety of autoimmune and inflammatory diseases, and therefore C5 or its receptor, C5aR1, has emerged as a potential target for drug development .