A) DNA and protein sequences of the myc-tagged mda-7/IL-24δ2,3,5 isoform. Potential start sites, including an alternative, and the ending site of translation are bolded and underlined. The protein sequence, which is similar to the last 36 aa of the full-length mda-7/IL-24 sequence, is shown in italic. c-Myc protein sequences derived from the vector in the Delta 2,3,5 and Mutant A constructs are shown in bold underlined lower case. Mutant A has a G→C mutation that changes the ATG initiation codon into ATC. Mutant B has a GATC insertion (highlighted), which induces a frame shift. B) MTT analysis of the viability of U2OS cells transiently transfected with vector (Control), the full-length mda-7/IL-24 isoform (IL-24), mda-7/IL-24δ2,3,5 (Delta2,3,5), or its mutant clones A and B. The viability assay was performed in triplicate after 94 hrs of transfection, and error bars show the standard deviation.