There is evidence that peptides containing PTMs, including phosphorylation, cysteinylation, and glycosylation, diversify a library of MHC‐bound peptides, which may be recognized by TCR and subsequently trigger cell activation.[81] During processes such as inflammation, cellular transformation, infection, apoptosis, and aging, alterations in the quantity and/or quality of PTMs can modify MHC‐associated peptides. The gene discussed is HLA-C; the disease is infection.