INS and obesity due to melanocortin 4 receptor deficiency: As Par-4-/- mice exhibit obesity, high glucose and insulin levels at 6 months (this study) and are reported to develop tumors in diverse tissues later as they age (9), our findings provide the groundwork for future studies to elucidate whether specific features associated with loss of Par-4 function in adipocytes not only promote obesity, but also serve as a risk factor for cancer.