JAK1 and drug hypersensitivity syndrome: •   A phase II RCT (NCT02708095) demonstrated efficacy in alleviating arthritis in active SLE patients•   A phase IIb study (PF-06700841) will investigate a selective JAK1 inhibitor in moderate-to-severe active SLE patientswithout renal or cerebral involvement who show inadequate response to standard therapies•   A phase II clinical trial on solcitinib (a selective JAK1 inhibitor) (NCT01777256) was discontinued owing to severe drugreaction with eosinophilia and systemic symptoms (DRESS) syndrome and hepatic function abnormalities