chondrocyte regulatory chondrocyte GitHub Copilot RegC A chondrocyte located mainly in the superficial zone of articular cartilage. In healthy human cartilage, regulatory chondrocytes are characterized by expression of EIF5A, PGK1, ANXA1, and TUBA1A. During osteoarthritis, a distinct subpopulation expands, marked by high expression of CHI3L1, CHI3L2, CRTAC1, and AEBP1, with enrichment for signaling pathway regulation (including Toll-like receptor, mTOR, and TGF-beta signaling) and antigen-processing gene expression, with a small proportion expressing MHC class II genes, suggesting potential immune cell-like regulatory functions during osteoarthritis progression.