BCL2 and lung cancer: In vitro studies have revealed that lung cancer cells can suppress the initiation of apoptosis by upregulating the anti-apoptotic protein Bcl-2, which blocks the release of apoptogenic cytochrome c; they can also inhibit apoptosis by downregulating pro-apoptotic proteins, such as Bax and Bak, thus promoting their survival within the bone marrow microenvironment (73, 74).