<prompt> Rituximab is used in the treatment ofMelanomaBasal cell carcinomaPemphigusChloasma  <response>: Rituximab Chimeric IgG monoclonal antibody targeting the B-cell surface antigen CD20 FDA approved for non-Hodgkins lymphoma, chronic lymphocytic leukemia, and RA unresponsive to other treatments Off-label dermatologic uses include bullous dermatoses especially pemphigus vulgaris and severe bullous pemphigoid, autoimmune connective tissue diseases, chronic graft-versus-host disease, vasculitis, and cutaneous B-cell lymphoma Depletion of B-cells occurs within 2 to 3 weeks of initial treatment with sustained depletion for an average of 6 months; B-cell numbers return to normal within the first year of treatment Relative contraindication in patients with history of bronchospasm, hypotension, or angioedema Pregnancy category C Common adverse effects include: hypeension, nausea, upper respiratory tract infection, ahralgia, pyrexia, and pruritus; most common are infusion reactions, which are generally mild and occur with the first infusion Patients with history of cardiac or pulmonary conditions should be more closely monitored as they are susceptible to severe infusion reactions Serious SEs: HBV reactivation, progressive multifocal leukoencephalopathy SJSTEN, serious infection, hepatic failure and myelosuppression. Ref:- Review of Dermatology by Alikhan pg num:-39,40 