Among them, some genes were highly dependent on BMI, such as ACTB, B2M, and GAPDH; some were highly dependent on the PCa existence, such as GUSB, IPO8, and KDM2B; and others varied in both conditions (e.g., HMBS and PPIG) and were, therefore, considered as the worst IRGs in PPATs under these different experimental conditions. The gene discussed is PPIG; the disease is posterior cortical atrophy.