According to the invention, parvoviruses such as the adeno-associated virus Type 2 (AAV2) are found to be oncolytic, selectively mediating apoptosis in cancer cells and their precursors, while leaving healthy cells intact. The invention also includes a method of killing cancer and other neoplastic and preneoplastic cells by administrating to said cells the AAV2 proteins Rep78 or Rep 68, expression constucts encoding the same, or pharmaceutical compositions comprising the same.
