GCK and myotonic dystrophy type 2: In this regard, a positive association was previously reported between DM2 and the up-regulation of HSP9049 on islets of Langerhans, since the overexpression of HSP90 on islets has been associated with elevation of β-cell ATP-sensitive potassium (KATP) channel expression50, enhanced insulin secretion, and promotion of glucokinase activation, the rate-limiting enzyme in glycolysis51.