TNF and leukemia: Subsequent studies have identified immunologic signatures associated with leukemia escape and relapse, including deregulation of co-stimulatory ligands (e.g. CD80, PD-L1), loss of response to GVL (IFNɣ) and tumor necrosis factor-ɑ (TNF-ɑ), and IL-2/STAT5 signaling (202, 206, 207).