SMAD4 and malignant colon neoplasm: To test our approach using disease-relevant genes, we built a series of multi[sh] constructs targeting Drosophila orthologs of four tumor suppressors recurrently mutated in colon cancer: TP53, APC, SMAD4 and SMAD2 (Drosophila orthologs p53, apc, Med and smox, respectively).