YAP1 and gastric cancer: While this gene has not been directly linked to Hippo, the related EphA2 receptor was shown to regulate YAP in breast and gastric cancer cells [23,24] and other EPHA receptors (EPHA4, EPHA5, EPHA7 and EPHA8) emerged as Hippo pathway activators in an siRNA screen in HEK293T cells [25].