EPHB2 and esophageal cancer: In esophageal cancer, the RKTG/PAQR3-induced inhibition of the Ras/Raf/MEK/ERK pathway impairs cell cycle transition from G1 to S phase, which is associated with the induction of cell cycle inhibitors p27 and p21 and the reduction of cyclin D1, CDK4 and CDK2 [63,64].