Figure 1B shows that the obesity significantly decreased GLUT4 levels in the endometrium under the IR condition; this finding was observed in women with or without PCOS, whereas MTF oral treatment was able to elevate GLUT4 levels in the endometrium under the IR state (p < 0.05). Even more, MTF treatment induced levels of GLUT4 higher than the levels observed in the control group (Figure 1B). This evidence concerns the gene SLC2A4 and obesity due to melanocortin 4 receptor deficiency.