To identify hub genes as methylation biomarkers, Xu et al. (2019) integrated PCa methylome data from TCGA (n = 500) with GEO (PCa n = 80 and control tissues n = 79) with a protein–protein interaction network [12], identifying six differentially methylated driver genes (AKR1B1, COL4A6, MAOB, GPX3, GSTM2, and RTP4). The gene discussed is RTP4; the disease is posterior cortical atrophy.