There are many kinds of tumor-specific promoters, including those for the genes encoding human telomerase reverse transcriptase (hTERT) [13,14,15,16,17], midkine [18,19], cyclooxygenase-2 [20], and survivin [21]; insertion of each of these promoters can selectively enhance the replication of adenovirus in tumor cells. Here, MDK is linked to neoplasm.