Tumor-specific, replication-competent oncolytic adenoviruses, including AdDelta24-p53 [66], SG600-p53 [67], and OBP-702 [68], are being developed as novel vectors for anticancer gene therapies; in these vectors, the promoters of cancer-related genes are used to regulate virus replication in a tumor-dependent manner. The gene discussed is TP53; the disease is neoplasm.