JAK2 and rheumatoid arthritis: Genome-wide association studies (GWAS) have established a relationship between the JAK-STAT pathway and IMIDs, For example, JAK2, Tyk2, STAT1, STAT3, STAT4, and IBD; TyK2, TAT1, SLE; TyK2, STAT4, RA; and TyK2, STAT3, and psoriasis are closely linked to the JAK-STAT pathway (Villarino et al., 2017).