Recently, an H1 histamine receptor antagonist and serotonin receptor blocker, cyproheptadine, has been reported for its anticancer activity, which resulted in the induction of cancer cell apoptosis in mantle cell lymphoma, leukemia, and multiple myeloma [13,14] and complete remission in two advanced HCC patients with lung metastases upon treatment with a combination of cyproheptadine and thalidomide [17]. Here, HRH1 is linked to leukemia.