HLA-C and rheumatoid arthritis: The role of citrullinated proteins and antibodies recognizing these proteins in the pathophysiology of RA is not fully understood, but specific human leukocyte antigen (HLA) alleles (HLA-DR4 and HLA-DR1, HLA-DR10 and HLA-DR14) have been linked to a predisposition to develop RA and the associated major histocompatibility complex (MHC) molecules were found to show increased ability to present peptides containing a citrulline residue [9,10].