HLA-C (Human Leukocyte Antigen C): HLA-C is a gene that encodes a protein in the MHC class I family, playing a crucial role in the immune system by presenting peptide antigens to CD8+ T cells. It also helps regulate natural killer (NK) cell activity through interactions with KIR receptors. The expression and diversity of HLA-C affect the effectiveness of the immune response, influencing susceptibility to infections, autoimmune diseases, and transplantation outcomes.