GAD1 and type 1 diabetes mellitus: However, 100% (14/14) of the reported cases exhibited undetectable islet autoantibodies, including ICA, IAA, anti-GAD antibody, anti-IA-2 antibody, and anti-ZnT8 antibody, which differs from previous reports on ICI-induced IDDM (Stamatouli, et al., 2018; Byun et al., 2020; Kotwal et al., 2019; Clotman et al., 2018; Gauci et al., 2017; de Filette et al., 2019).