Background: Programmed cell death or apoptosis is one of the most important physiological processes involved in development and homeostasis maintenance of multicellular organisms. Every defect in apoptosis regulation leads to wide variety of genetic disorders, autoimmune diseases and cancers. Apoptosis is an essential process in both health and diseases. Apoptosis is defined as morphological changes in a cell undergoing programmed cell death. These changes lead to cell shrinkage, nuclear condensation, membrane intrusion, plasma membrane fractionation and their conversion to apoptotic bodies and changes in cell surface membrane which cause phagocytosis of the cell bearing apoptosis. Materials and Methods: Apaf-1 gene is mutated using PCR and then transfected into HEK293T cells by lipofectamin. 24 h transfected cells exposed to doxorubicin and caspase 3/7 activity was measured over different times. Result: Caspase 3/7 activity was observed obviousely in transfected cells, which was 3 fold greater than those of controls. This data demonstrates the increase in caspase 3/7 activity in HEK293T cells. Based on our observation, the terminus domain in Apaf-1 is probably play a role in releasing the caspases. Conclusion: The results of this study indicated that terminal domain of Apaf-1 has pivotal role in caspase regulation and it is possible to design a biosensor for screening the anticancer drugs by removing terminal domain of this protein.