HCG9 and rheumatoid arthritis: Cluster 5, which includes genes at 6p22.1 (HLA-A, HCG4P5, HLA-T, MOG, TRIM26, HCG9, IFITM4P), demonstrated further connections between JIA and a subset of autoimmune/inflammatory traits (i.e., type 1 diabetes, asthma, eczema, and severe COVID-19 or rheumatoid arthritis).