What is the meaning of MHC?

MHC stands for Major Histocompatibility Complex, a set of genes that play a crucial role in the immune system by presenting peptide fragments from pathogens on the surface of cells. This allows T cells to recognize and respond to infected or abnormal cells, facilitating an immune response. There are two main classes of MHC molecules: Class I, which presents to CD8+ cytotoxic T cells, and Class II, which presents to CD4+ helper T cells. MHC is essential for immune system functioning and plays a significant role in tissue compatibility for organ transplantation.