EGFR and posterior cortical atrophy: In cancer, significant pathway enrichment was seen in both low and high expression tiers, with polycomb repressive complex 2 (PRC2) targets and genes known to be downregulated in PCa enriched in the lowest expression tier while pathways related to cell motility, BARD1 and ErbB1 signaling, and genes known to be enriched in PCa specifically were observed in the highest expression tier (Fig. 3d).