The wild-type mice results are more similar to the situation in humans where obesity is associated with elevated levels of leptin, representing a form of leptin resistance [55, 56], as opposed to the ob/ob mouse model where the lack of leptin is associated with extreme obesity (see [30, 31], Ngo et al., 2014; unpublished results). This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.