GPRC6A and Insulin resistance: Human ucOCN can bind and activate human GPRC6A (De Toni et al., 2016) and promotes beta cell proliferation and insulin synthesis in human islets (Sabek et al., 2015), while mutations or polymorphisms in human GPRC6A are associated with insulin resistance (Di Nisio et al., 2017; Oury et al., 2013a).