LEAP2 and type 1 diabetes mellitus: Circulating LEAP2 levels in mice decrease with fasting (Ge et al., 2018; Islam et al., 2020; Mani et al., 2019; Fernandez et al., 2022), whereas plasma LEAP2 is increased in DIO (Mani et al., 2019; Holá et al., 2023; Casado et al., 2024) and ob/ob mice (Lugilde et al., 2022), and in a mouse model of type 1 diabetes mellitus (T1DM) (Mani et al., 2019).