Major Histocompatibility Complex class I (MHC-I) molecules bind and present peptides to cytotoxic T cells. protecting against pathogens and cancer. MHC-I is highly polymorphic and each allotype is promiscuous. and capable of binding a unique and diverse repertoire of peptide ligands. https://www.roneverhart.com/Short-Porch-Mortar-USSSA-Pro-M-12-Slowpitch-Softballs/