There are reports of patients developing psoriasis after rituximab therapy, but there are also cases whose cutaneous lesions and psoriatic arthritis partially improved after taking rituximab.26,27 Interleukin-10-secreting regulatory B cells mediate the suppression of autoimmune and inflammatory diseases by inhibiting Th1 and Th2 cytokine polarization, antigen presentation, and proinflammatory cytokine production by monocytes and macrophages. The gene discussed is IL10; the disease is psoriatic arthritis.