HLA-C and autoimmune disease: To the best of ourknowledge, our study is the first systematic analysis of the impactthat PTMs have on MHC binding in a whole cell context and how PTMscan also alter T cell activation using live target and effector cells.Provided that negative selection is age-dependent and becomes increasinglydiminished past adolescence, it is evident that PTMs could be causalevents that result in autoimmune diseases.