Histamine treatment non-significantly increased IFNγ production in tumours, while no changes were observed in other important cytokines related to cancer progression, such as TNFα.46,47 IFNγ is involved in the promotion of hosts’ antitumour immunity and in the cancer elimination (immunosurveillance) process, considering its antiproliferative and proapoptotic effects.5,6,48 In vitro, 4T1 cells produced no detectable levels of this cytokine (data not shown). The gene discussed is TNF; the disease is neoplasm.