EGFR and neoplasm: Over-activation of the mitogenic EGFR signaling pathway can establish a tumor model in the fly midgut [2, 50, 51], therefore, a constitutively active form of Ras oncogene at 85D (also known as RasV12) was induced by esgts>Gal4 to activate EGFR signaling pathway in the progenitor cells.