In agreement with the transcriptomic data on the dynamic changes of C4 cells in the papain-induced lung inflammation course (Fig. 1g), the CD45+Lin−IL-7Rα+IL-33R+CD25+PD-1hiCD69hiNr4a1+ cells were primarily detected on d7 (Fig. 3h and i), suggesting they were C4 cells. This evidence concerns the gene IL1RL1 and inflammatory response.