NTSR1 and obesity due to melanocortin 4 receptor deficiency: At 4 weeks, several obesity-related genes and genes involved in the control of feeding behavior were significantly affected in cKO mice; Lpr and Pmch were up-regulated, as were Nts and its receptor Ntsr1. These genes are known to be crucial for maintaining proper energy balance and Lpr has been previously shown to be under the control of miR-200a [29,31,32].