The high relative frequency of regulatory T cells in PDAC is consistent with previous observations in mouse models and human, and in agreement with the notion that regulatory T cells, together with myeloid cells, are key immunosuppressive components in PDAC.42–45 More importantly, the regulatory T cells in pancreatic tumors expressed high levels of ICOS, which highlights the potential use of ICOS antagonists to inhibit Treg interactions with ICOSL (such as NCT03829501). The gene discussed is ICOSLG; the disease is pancreatic neoplasm.