FNDC5 and cancer: Finally, in order to empirically confirm that the selected IRGs were suitable to be used in expression analyses of PPATs obtained under different experimental conditions (i.e., patients with different BMIs or with and without PCa), we measured the expression levels of six metabolic- and tumor-related genes well-known to be dysregulated in the AT of humans under cancer-related conditions (i.e., SPP1, IL6R, CD68, AGT, FNDC5, and RETN [18,19,20,21,22,23]; primers sequences are listed in Table S2).