Great success has been achieved in the development of covalent irreversible BTK inhibitors for the treatment of hematological malignancies, as exemplified by ibrutinib, the first effective and selective BTK inhibitor approved by the Food and Drug Administration (FDA) in 2013 to control a variety of B-cell tumors [5,7,8,9,10]. The gene discussed is BTK; the disease is hematologic disorder.