CXCL1 and glioblastoma: Among the 40 cytokines that were screened, CXCL1 was the most actively upregulated cytokine; it plays an essential role in recruiting CXCR2‐positive myeloid inflammatory cells, including neutrophils, monocytes and macrophages, and inducing local angiogenesis (Figure5A,B; Figure S5A,B,C, Supporting Information).[15] To identify the cytokines secreted by SnAs that were responsible for increased CXCL1 production in GBM cells, we treated GL261 cells with these cytokines (gradient increase in concentrations) and tested CXCL1 levels via ELISA.