In islets from type 2 diabetes, haploinsufficiency of CR6-interacting factor 1 (CRIF1), which encodes a mitochondrial ribosome protein, is associated with reduced mitochondrial respiration (Hong et al. 2022), and in cultured hepatocytes derived from liver-specific CRIF1 knockout mice, the mitochondrial maximal respiratory capacity was significantly lower compared to the WT control (Song et al. 2022). Here, GADD45GIP1 is linked to type 2 diabetes mellitus.