Intracranial response rates range from 6 to 25% in melanoma BM patients treated with ICI monotherapy [2–6], 33% in non-small cell lung cancer (NSCLC) patients [7], and 53–57% in asymptomatic melanoma BM patients treated with a combination of anti-CTLA-4 and anti-PD-1 ICI [8, 9], although symptomatic BM patients show lower efficacy but responders could derive long-term benefit [8, 10]. The gene discussed is CTLA4; the disease is melanoma.