S100 calcium-binding protein A7A (S100A7A)

S100 calcium-binding protein A7A (S100A7A), also known as koebnerisin, is a member of the S100 family of calcium-binding proteins highly expressed in epithelial tissues such as the skin and breast[5]. It plays a role in epithelial homeostasis, innate immunity, and antimicrobial host defense by acting directly as an antimicrobial peptide, especially against *E. coli*[5]. Koebnerisin is overexpressed in inflammatory skin diseases (including psoriasis, where it contributes to the \"Koebner phenomenon\") and certain breast cancers, where its secretion functions as a chemoattractant that enhances inflammation and may drive tumor progression in hormone receptor–negative tumors. S100A7A is closely related at the sequence and functional level to S100A7 (psoriasin), but is distinct in regulation, expression, and function[5]. It acts as a proinflammatory amplifier in the epithelium, attracting myeloid immune cells, and participates in tissue regeneration, maturation, and tumorigenesis in human epithelial tissues[5].

Other names

Protein S100-A7AS100A15S100A7L1S100A7fS100 calcium-binding protein A15S100 calcium-binding protein A7-like 1koebnerisinNICE-2NICE2

No approved pharmacological agents targeting S100A7A directly\n- As a chemoattractant, S100A7A signals through a Gi protein-coupled receptor (pertussis toxin-sensitive pathway) to attract myeloid leukocytes\n- Contributes to inflammatory amplification with S100A7 via RAGE-dependent mechanisms[5]