In clinical practice, it has also been shown that T1DM is far more common with PD‐1 inhibitor monotherapy and PD‐1/CTLA‐4 inhibitor combination therapy than CTLA‐4 inhibitors only, though de Filette and colleagues do report three cases of T1DM caused by CTLA‐4 inhibitor monotherapy [8, 12]. The gene discussed is CTLA4; the disease is type 1 diabetes mellitus.