BCL2 and B-cell chronic lymphocytic leukemia: Overexpression of the Bcl-2 gene is inherent to various cancers, for example, 90% of colorectal adenocarcinomas, 80% of undifferentiated nasopharyngeal cancers, 70% of breast adenocarcinomas and chronic lymphocytic leukaemias, 60% of gastric cancers, 30–60% of prostate cancers, and in varying percentages of melanomas, blastomas, and kidney cancers [94].