GRN and obesity due to melanocortin 4 receptor deficiency: In particular, hyperprogranulinemia could be involved in the pathogenesis of obesity-associated insulin resistance, impairing insulin signaling and insulin-induced glucose uptake both in vitro and in vivo, whereas PGRN deficiency could protect from high fat diet-induced insulin resistance (Qu et al., 2013; Korolczuk and Bełtowski, 2017).