Herein, we provide a detailed review, describing the clinical trials that led to the FDA approval of the BTK inhibitors for management of Chronic Lymphocytic Leukemia (CLL), Mantle Cell Lymphoma, Marginal Zone Lymphoma (MZL), Follicular Lymphoma (FL) and Waldenstrom Macroglobulinemia (WM). This evidence concerns the gene BTK and Waldenstrom macroglobulinemia.