Downregulation of the miR-15 family has been described in other solid tumors like lung, colon, ovary, and prostate, and the gene locus has been shown to be deleted in more than half of B cell chronic lymphocytic leukemias (CLLs) [60, 77]; in the latter, the miR-15a/16-1 cluster targets the oncogene BCL2 and functions as a tumor suppressor [142]. This evidence concerns the gene BCL2 and B-cell chronic lymphocytic leukemia.