CASP3 and cancer: Once cells were preconditioned with Y-27632, Dox addition could not increase p-Akt, Bcl-2, or cleaved Caspase-3 to the same levels as it did without Y-27632, indicating that: (1) Y-27632 protects cells likely by inhibiting Dox-induced upregulation of cleaved Caspase-3, possibly not through Akt/Bcl-2 pathway and (2) The increased expression of p-Akt and Bcl-2 after Dox treatment may demonstrate the successful development of a drug resistant system (a common protective machinery in cancer cells against chemotherapy, see Discussion below) in cardiac stem cells.