We examined cytotoxic activities of replication-competent AdF35 and Ad5 on esophageal carcinoma cells, and compared the activities between Ad5/MK and AdF35/MK (Fig. 1), and Ad5/Sur and AdF35/Sur, with the same cells (Additional file 1: Figure S1). Here, PSEN2 is linked to carcinoma of esophagus.