Early studies found that circulating resistin levels are elevated in genetic and DIO in mice (Steppan et al., 2001) and obese humans (Degawa-Yamauchi et al., 2003; Owecki et al., 2011; Sadashiv et al., 2012) whereas other studies found that resistin is downregulated in human obesity (Way et al., 2001; Ye et al., 2013) and rodent obesity (Milan et al., 2002; Maebuchi et al., 2003). The gene discussed is RETN; the disease is obesity due to melanocortin 4 receptor deficiency.