The most common cause of paraneoplastic chorea is anti-collapsin response-mediator protein 5 (anti-CRMP-5; anti-CV2) immunoglobulin (Ig) G. Hemichorea has been noted in case reports of patients with small cell lung cancer [81] and diffuse large B-cell lymphoma [82]. The gene discussed is GAN; the disease is diffuse large B-cell lymphoma.