IGF1 and obesity due to melanocortin 4 receptor deficiency: Moreover, several of the candidate genes are associated with obesity in humans, including DNAH8 (Söhle et al., 2012), IGF1 (Berryman et al., 2013), KCNH1 (Vasconcelos et al., 2016), LRRC8C (Hayashi et al., 2011), NTRK2 (Gray et al., 2007), and PRIP (Yamawaki et al., 2017) suggesting that they play a role in controlling energy homeostasis and potentially differences in body fat levels across environments.