MC4R and obesity due to melanocortin 4 receptor deficiency: Re-introduction of MC4R into Kiss1 neurons in Kiss1Cre: Mc4rloxTB mice completely recovered estrous cyclicity, which was similar to controls (diestrus: p = 0.1932, proestrus: p = 0.8262, estrus: p = 0.0547, compared to controls; Figure 3E,Figure 2—figure supplement 1C, D) despite Kiss1Cre: Mc4rloxTB mice showing the same degree of obesity as Mc4rloxTB mice (Figure 3D), indicating that obesity per se was not mediating the irregular estrous cycles in Mc4r KO mice.