INS and type 2 diabetes mellitus: Given that autocrine insulin action is critical in maintaining normal β-cell function [16], [17], and that β-cell insulin resistance can deteriorate β-cell function that accelerates the progression of diabetes [53], [54], future studies are required to determine whether the impairment of the autocrine insulin-GABA-GABAAR signaling contributes to β-cell insulin resistance in type 2 diabetes.