Among 213 patients with NSCLC, MM, RCC, and GC, who had received anti-PD-1/PD-L1 antibody monotherapies, 209 patients with NSCLC (n = 112), MM (n = 35), RCC (n = 33), and GC (n = 29) were reviewed in this study after exclusion of 1 patient with prior treatment with an anti-CTLA-4 antibody and 3 patients who did not have prior CT within 1 year of ICI administration. The gene discussed is CTLA4; the disease is Miyoshi myopathy.