ARF6 and neoplasm: In an effort to further elucidate how Egfr promotes oncogenic Ras-driven tumour overgrowth, we knocked down Egfr effectors (Drk and Arf6) by RNAi and asked whether this suppress oncogenic Ras-mediated tumour overgrowth, and identified Arf6 as a mediator of Ras tumour overgrowth.