INS and Hypoinsulinemia: Unlike the mice with global or pancreatic Brsk2 deletion, which exhibit hypoinsulinemia and glucose intolerance (Nie et al., 2013c), mice with ablation of Brsk2 in mature β cells exhibit slightly increased serum insulin levels in response to hyperglycemia under normal chow-diet condition (Figure 3F), indicating that the regulation of insulin secretion by BRSK2 involves more comprehensive secretory machineries of mature β cells (Nair et al., 2019; Sdao et al., 2021).