CD8A and bladder transitional cell carcinoma: Data extracted from TCGA database provided the cellular content of B cells, CD4+ memory T cells, CD8+ T cells, macrophages, mesenchymal stem cells, natural killer T cells, regulatory T cells, type-1 T-helper cells, and type-2 T-helper cells in BLCA, KIRC, KIRP, and TGCT tissues.