INS and type 2 diabetes mellitus: Other pancreatic β-cell proliferation regulators include miR-24, which is highly expressed in pancreatic β-cells, further upregulated in the islets of genetic fatty db/db mice, and inhibits β-cell proliferation and insulin secretion by binding to two maturity-onset diabetes of the young genes, Hnf1α and Neurod1. Meanwhile, the expression of miR-24 increased from 2.0- to 3.5-fold in 8- and 12-week-old db/db mice, showing an increase with the aging of db/db mice [19].