Among the four types of recombinant Ads, rAdF35-E1-2A-GFP-ADP, which contained the E1A gene fused with the 2A peptide-coding sequence, the GFP gene in the E1 region and the ADP gene in the E3 region, mediated the highest GFP expression in the human cultured tumor cells, and detected CTCs in the blood samples at levels comparable to rAdF35-142T-GFP developed in the previous study [6]. This evidence concerns the gene DHTKD1 and neoplasm.