However, novel targeted therapeutics approved for treatment-naïve CLL and/or refractory or relapsed CLL (R/R CLL) are ibrutinib, which inhibits Bruton-agammaglobulinemia-tyrosine-kinase (BTK); idelalisib, which inhibits p110 d isoform-specific phosphoinositide-3 kinase (PI3K); and venetoclax, an inhibitor of anti-apoptotic protein B-cell lymphoma 2 (BCL-2) [22]. This evidence concerns the gene BTK and B-cell chronic lymphocytic leukemia.