In contrast, statistical differences were consistently found in the expression levels of GUSB, HMBS, IPO8, KDM2B, and PPIG (using both RT-qPCR and microfluidic-based qPCR array, methodologies) as well as ACTB, HSP90AB1, RPS13, and YWHAZ (using one of the methodologies) when classifying patients in BPH vs. PCa (Figure 2b), suggesting that all these IRGs are not good candidates to be used in these expression analyses. This evidence concerns the gene PPIG and benign prostatic hyperplasia.