CAFs expressing GS associates with the elevated abundance of pro-tumorigenic TAMs. (A) Correlation analysis of GS transcriptomic expression level and pro-tumorigenic TAMs signature of colorectal cancer, lung cancer, and prostate cancer patients in TCGA datasets. (B and C) Distance of M2-like macrophages (CD163⁺CD68⁺, red) and M1-like macrophages (CD163⁻CD68⁺, green) from GS⁺ fibroblasts (yellow). Scale bars, 50 μm (B), and quantification of distance (C). (D) qPCR analysis of relative mRNA level of genes (Slc1a5, Gls1, and Glud1) (n = 4) involved in glutamine consumption pathway in macrophages sorted from spleen or Yumm1.7 melanomas. (E) Knockout of GS expression in CAFs by using lentivirus infection validated by western blot. (F) Glutamine levels in spent medium of CAF-WT and CAF-GS^KO cultured in TCM for 24 h, normalized to unspent medium. Data in A are analyzed with Spearman correlation test. Data are representative of at least two independent experiments with similar results (D–F). Data are shown as mean ± SEM and were analyzed by two-tailed, unpaired Student’s t test (C, D, and F). ****P < 0.0001; **P < 0.01; P > 0.05 not significant (ns). Source data are available for this figure: SourceData FS3.