EPHA2 and cancer: In the absence of ligand stimulation, the EGFR/MAPK/PI3K pathway phosphorylates the serine-897 residue of EphA2 (pS897-EphA2, termed ligand-independent oncogenic signaling) to promote cell proliferation, survival, motility, and chemoresistance through the activation of RhoG/RACK signaling pathways (5, 6) ultimately stimulating malignant tumor progression.