Furthermore, blockade of G‐CSF in tumor cell culture supernatant/neutrophil co‐culture efficiently inhibited the induction of PD‐L2 on neutrophils; provision of exogenous G‐CSF into non‐tumor cell culture supernatant/neutrophil co‐culture significantly increased PD‐L2 expression on neutrophils (Figure 5G; Figure S11D, Supporting Information); STAT3 was predominantly phosphorylated in neutrophils after treatment with tumor cell culture supernatants, and this phosphorylation was abolished when blocking G‐CSF (Figure 5I). This evidence concerns the gene PDCD1LG2 and neoplasm.