In patients with lymph node-negative breast cancer, oropharyngeal squamous cell carcinoma, chronic lymphocytic leukemia, glioblastoma multiforme and prostate cancer the A allele has been associated with higher Bcl-2 expression levels and the−938 C > A polymorphism has been associated with survival of patients suffering from these cancers[16-20]. This evidence concerns the gene BCL2 and B-cell chronic lymphocytic leukemia.