IL4I1 and cancer: At last, we evaluated the correlation between IL4I1 level and the abundance of 28 types of TILs in different human cancers in the TISIDB database, and the results was shown in Fig. 5C. From Fig. 5D, we saw that the high IL4I1 level was correlated with more myeloid-derived suppressor cells (MDSC, r = 0.831), Tregs cells (r = 0.797), macrophage (r = 0.77), CD8+ T cells (r = 0.705), CD4+ T cells (r = 0.678), mast cells (r = 0.659), neutrophil (r = 0.639), B cells (r = 0.648), and plasmacytoid DC (pDC, r = 0.393) (all p < 2.2x10–16).