We then explored the crucial biomarkers of MRS1-tumor cells, finding that S100A7, S100A8, and PTTG1 were up-regulated in the MRS1 phenotype both in bulk data (TCGA-BLCA and GSE13057) and single-cell data (Fig. 5D, Supplementary Fig. 9B, Supplementary Tables 1, 3, 4). This evidence concerns the gene PTTG1 and bladder transitional cell carcinoma.