Critical TKs include the fusion chimera oncoprotein BCR-ABL1 in CML [8] and the B-cell receptor (BCR) signaling pathway including Bruton Tyrosine Kinase (BTK) [9] and phosphatidylinositol 3-kinase (PI3K) in CLL [10]. The gene discussed is PIK3CD; the disease is B-cell chronic lymphocytic leukemia.