EPHB2 and cancer: Another investigation revealed that circMELK is up-regulated in GBM, acting as a sponge for tumor suppressor miR-593, to increase the oncogenic gene Eph receptor B2 (EphB2), a member of Eph receptor tyrosine kinases family identified as a regulator of cancer stemness, drug resistance and subsequently glioblastoma EMT and GSC maintenance (105).