For the piriform cortex, unique pathways included extracellular receptor kinase/mitogen-activated protein kinase (ERK/MAPK) signaling; fibroblast growth factor (FGF) signaling; G-protein coupled receptor signaling; glioma invasiveness signaling; glycerophospholipid metabolism; IL-1 signaling; neuropathic pain signaling in dorsal horn neurons; peroxisome proliferator-activated receptor-α/retinoid × receptor-α (PPARα/RXRα) activation; and taurine and hypotaurine metabolism (Additional File 11). This evidence concerns the gene RXRA and glioma.