AREG and obesity due to melanocortin 4 receptor deficiency: While we did not observe overexpression of estrogen synthetic enzymes or classical estrogen receptor (ER) targets (e.g., PR, AREG, GREB1, or TFF1) (Additional File 1: Table S7) in breast samples from OB ADOL, several additional pieces of data suggested that signaling pathways downstream of the ER may, in fact, be activated in obesity.