Of note, previous results on genetic association between CIITA and risk for multiple sclerosis, rheumatoid arthritis and myocardial infarction show a similar direction of effect as found in our congenic rat model, with the risk allele in CIITA being associated with lower expression of CIITA, CD74, HLA-DRA and HLA-DQA1. Here, CIITA is linked to rheumatoid arthritis.