MMP9 and posterior cortical atrophy: Importantly, these changes observed in the expression levels of ANGPT1, LEP, MMP2, and MMP9 after normalization were not observed when the data were not normalized (raw data) (Figure 6a–d), which again clearly indicates the necessity of using suitable IRGs for normalization of gene expression levels in PPATs under different experimental conditions (i.e., presence or absence of Ob and PCa).