EPHA7 and posterior cortical atrophy: Prior studies have shown that the optimum ligand of EphA7 is ephrinA5.15 We explored whether the optimum ligand of EphA7 is also ephrinA5 in PCa, whether the phosphorylation of EphA7 receptors is related to the stimulation of endogenous ephrinA5 ligand in a cell–cell contact-dependent manner and whether the exogenous ephrinA5 ligand can further elevate the level of EphA7 tyrosine phosphorylation.