BCL2 and B-cell chronic lymphocytic leukemia: Although del13q14 has unraveled the relevance of the apoptotic pathway in the disease and its assessment by Fluorescent In Situ Hybridization (FISH) is recommended by guidelines [21], this genetic alteration is not currently used as a biomarker for precision medicine, since CLL responds to BCL2 inhibitors independent of del13q14 status.