The present invention is related to the use of a virus, preferably an adenovirus, for the manufacture of a medicament, whereby the virus is replication deficient in cells which do not have YB-1 in the nucleus, and the virus codes for an oncogene or oncogene product, in particular an oncogene protein, which transactivates at least one viral gene, preferably an adenoviral gene, whereby the gene is selected from the group comprising E1B 55 kDa, E4orf6, E4orf3 and E3ADP.