Although it is unknown whether these circulating MP Tfh cells are established from previous infection or developed directly from naïve CD4 T cells, the expression patterns of T‐bet and Foxp3 were similar to mouse MP Tfh cells: Some circulating Tfh cells expressed Foxp3, but circulating Tfh cells hardly expressed T‐bet (Figure 7B). Here, FOXP3 is linked to infection.