BTK and chronic idiopathic urticaria: Thirteen compounds targeting BTK in 9 indications having attained clinical trial status of phase 2 or beyond were found that encompass RA, SLE, MS, PV, SJ chronic spontaneous urticaria (CSU), idiopathic thrombocytopenia (ITP), graft versus host disease (GVHD) disease, and asthma indications (Table 1).