OXTR and obesity due to melanocortin 4 receptor deficiency: Oxytocin receptor or OT deficient mice are associated with adult-onset obesity (Kasahara et al., 2007; Takayanagi et al., 2008; Camerino, 2009; Sun et al., 2019) that appears at 8 (Tamma et al., 2009), 10 (Kasahara et al., 2007) or 16 weeks (Camerino, 2009) in OT null mice and 12 weeks in OTR null mice (Takayanagi et al., 2008).