In order to clarify whether the enhanced tumor cell lysis mediated by the novel tribodies is correlated to the increased activation of lymphocytes, we measured the levels of IFNγ, as a marker of hPBMCs functionality [32], released in the supernatants of these co-cultures, by comparing the effects of the novel tribodies with those of the parental mAbs when used in combination with parental tribody Tb535H. The gene discussed is IFNG; the disease is neoplasm.