This screen identified many novel potential tumor suppressor genes, and we verified that 80 out of the top 100 genes whose orthologs were downregulated in human cancer were able to cooperate with RasV12 to promote epithelial tissue overgrowth in Drosophila. One of these conserved tumor suppressor genes was Drosophila Tsp29Fb, the mammalian ortholog of which is TSPAN6 (TM4SF6) [14]. This evidence concerns the gene TSPAN6 and cancer.