In patients who were being treated with anti-PD1/PD-L1 antibodies in monotherapy, the median time to ICI-induced IDDM onset was 3.9 months (95% CI 0.4–7.4), whilst in patients treated with anti-PD1/PD-L1 and anti-CTLA4 antibodies in combination, the median time to ICI-induced IDDM onset was 1.4 months (95% CI 0.9–1.8) (p = 0.05). The gene discussed is CTLA4; the disease is type 1 diabetes mellitus.