Interestingly, we further found that in Treg from tumors CD103 no longer distinguished between Helios− and Helios+ Treg (data not shown), a finding consistent with recently published data [22], but which compromised our ability to perform functional analyses of Helios+ versus Helios− Treg derived from the tumor-infiltrating population. The gene discussed is IKZF2; the disease is neoplasm.