We validated this result through flow cytometry in an independent cohort of patients with HCC (Supplemental Table 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.167967DS1): CD71 expression in tumor-infiltrating OX40+ Tregs was significantly higher than OX40+ Tconvs or OX40– Tregs and tended to be higher also than OX40+ Tregs in peripheral blood (PB), where they were represented at very low frequency (12, 13) (Figure 1B). Here, TFRC is linked to neoplasm.