However, we found CD71 was an inadequate marker for tissue resident immature cells, as it was also expressed on erythroid cells within the circulation (Supplementary Fig. 1A) and furthermore, was significantly downregulated on infection (p = 0.04, p = 0.005; paired t-test infected vs uninfected splenic cells in EryB and EryC, respectively, Supplementary Fig. 1B). The gene discussed is TFRC; the disease is infection.