Tumor microenvironment, tumor immune infiltration, immune checkpoint molecules, and immune cell pathways

Based on the TIMER database, the relationship between ETS1 expression in ccRCC and six types of immune-infiltrating cells, including B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells, was analyzed. TISIDB (http://cis.hku.hk/TISIDB/) was used to explore ETS1 expression in tumor tissues and tumor-infiltrating lymphocytes (TILs) [27]. Following the gene expression profile analysis, we employed gene set variation analysis to assess the TILs’ relative abundance. We used Spearman’s test to investigate the correlation between ETS1 and TILs. The expression matrix of ETS1 was utilized to compute the ImmuneScore, StromalScore, and ESTIMATEScore through the ESTIMATES algorithm, with a cut-off value of P < 0.001 [28]. We also calculated immune cell infiltration in ccRCC using CIBERSORT with P < 0.001 as the cutoff value [29]. We conducted these analyses using the ‘limma’ R package and visualized this using the ‘reshape2’ and ‘RColorBrewer’ R packages. The aforementioned analyses were performed using the Sangerbox tools (http://www.sangerbox.com/tool).