The formation, overgrowth and metastasis of tumors comprise a complex series of cellular and molecular events resulting from the combined effects of a variety of aberrant signaling pathways, mutations, and epigenetic alterations. Modeling this complexity in vivo requires multiple genes to be manipulated simultaneously, which is technically challenging. Here, we analyze how Drosophila research can further contribute to identifying pathways and elucidating mechanisms underlying novel cancer driver (risk) genes associated with tumor growth and metastasis in humans.Work in the authors laboratory is supported by the Spanish Ministry of Economy and Competitiveness and co-financed by FEDER funds (BFU2015-64239-R, the Spanish State Research Agency, through the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2013-0317), the Scientific Foundation of the Spanish Association Against Cancer (AECC) (CICPF16001DOMÍ), and the Valencian Regional Government’s Prometeo Programme for research groups of excellence (PROMETEO/2017/146) to M.D.Peer reviewe