Arthralgias, arthritis (350) (including inflammatory arthritis (371); autoantibodies to IFN-I, ANA (Ro, La, Jo-1, P1, and U1-snRNP) may be seen in PASC (310); SLE (371); MIS-C (367); MIS-A (413). The gene discussed is BTG3; the disease is systemic lupus erythematosus.