BCL2 and neoplasm: The bcl-2 G-quadruplex DNA, a secondary structure of G-rich sequence in promoter of Bcl-2 gene via Hoogsteen hydrogen bond, is a key director to regulate the expression of Bcl-2, which is a crucial member of the Bcl-2 family of proteins to inhibit the apoptosis and usually over-expressed in various human tumor cells [8].