BTK inhibitors (Ibrutinib, Acalabrutinib, Zanubrutinib, Pirtobrutinib) represent a promising therapeutic target for various B cell malignancies (chronic lymphocytic leukemia, small lymphocytic lymphoma, marginal zone lymphoma, diffuse large B cell lymphoma, and follicular lymphoma), Waldenstrom macroglobulinemia, and multiple myeloma. The gene discussed is BTK; the disease is B-cell chronic lymphocytic leukemia.