RBP4 and obesity due to melanocortin 4 receptor deficiency: Two-way ANOVA analysis found no statistically significant effect of PCOS status on GLUT4 expression (p = 0.1997) nor any statistical interaction between PCOS status and obesity (p = 0.1318), although GLUT4 expression levels were higher in women in the lean control group than in any of the other three groups, as noted for RBP4 (Figure 3B).