Rituximab was approved for medical use in 1997. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Rituximab, sold under the brand name Rituxan among others, is a medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin's lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, idiopathic thrombocytopenic purpura, pemphigus vulgaris and myasthenia gravis. Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. When it binds to this protein it triggers cell death.