In general the up regulation of anti-apoptotic proteins leads to the prevention of apoptosis which can be solved by inhibitors and the down regulation of anti-apoptotic proteins leads to the induction of apoptosis which is reversed by activators that are able to bind and modify their activity. An important target molecule in apoptosis based therapies is Bcl-2 for drug design. Bcl-2 was the first oncogene found to cause cancer-inhibiting apoptosis. It is over expressed in tumors and is resistant to chemotherapy. Scientists have found that binding depressors to Bcl-2 anti-apoptotic proteins inhibits them and leaves direct activators free to interact with Bax and Bak.