The rare, high-expression rs5844572_CATT7 allele was shown to be associated with severe forms of steroid resistance in the course of Japanese ulcerative colitis patients [42], with increased MIF expression in more severe forms of glomerulonephritis [43], and with early onset of rheumatoid arthritis [44], while the wild, low-expression CATT5 allele correlated with milder forms of a disease in the latter studies. Here, MIF is linked to rheumatoid arthritis.