Through retrospective clinical research and systematic reviews, prior studies have concluded that ICI-DM frequently occurs in the setting of exposure to anti-PD-1/PD-L1, either alone or in combination with other immunotherapies, and emerged infrequently after anti-CTLA-4 (Stamatouli et al., 2018; Marchand et al., 2019; Quandt et al., 2020). Here, CTLA4 is linked to diabetes mellitus.