In contrast, mice lacking the BB1 receptor showed no alterations in food intake or body weight gain (Ohki-Hamazaki et al., 1999), however, human genetic studies support a strong association between polymorphisms on the NMB gene and increased adiposity and obesity (Bouchard et al., 2004; Spálová et al., 2008; Pigeyre et al., 2010). The gene discussed is NMB; the disease is obesity due to melanocortin 4 receptor deficiency.