Fig 1: CHI3L1+ stromal cells in immunosuppressive bladder tumor microenvironment. (a) Gene set enrichment analysis results reveal the enrichment of the ‘Exhausted CD8+ T‐cells’ pathway in urothelial carcinoma of the bladder (UCB) patients with high CHI3L1 expression in the TCGA‐BLCA cohort. (b) Scatter plots illustrate the association between CHI3L1 expression and the presence of CD8+ T cells. (c) Heatmap displaying immune‐suppressive genes and their expression to CHI3L1 in the TCGA‐BLCA cohort. (d) Representative images depicting the presence of CHI3L1+ stromal cells (SCs), PD‐L1+ immune cells (ICs), PD‐1+ TIL and CD8+ TIL infiltration in UCB tissues. Scale bars, 50 μm. (e–g) Associations of combined CHI3L1+ SCs with PD‐L1+ ICs, PD‐1+ TILs or CD8+ TILs with lymph node (LN) metastasis in UCB tissues. (h, i) Prognostic value of combined CHI3L1+ SCs with PD‐L1+ ICs for overall survial (OS) (h) and recurrence‐free survival (RFS) (i) in UCB tissues. (j) Representative images of four‐colour MIF staining displaying CHI3L1 (red), VSITA (green), TIGIT (yellow) and CK (white), with counterstaining using DAPI (blue). Scale bars, 50 μm. (k) Representative images of four‐colour immunofluorescence staining revealing CHI3L1 (red), TIM‐3 (green), LAG‐3 (yellow) and CK (white), with counterstaining using DAPI (blue). Scale bars represent 50 μm. Statistical significance was determined by the unpaired t‐test and is indicated by P‐values. *P < 0.05; ***P < 0.001.