The results suggested that TAP1 was a risk factor for patients with ACC, DLBC, KIRP, low-grade glioma (LGG), lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), PAAD, and UVM, as higher expression of TAP1 mRNA was correlated with poor prognosis, as well as a potential protective factor in bladder urothelial carcinoma (BLCA), BRCA, clear cell renal cell carcinoma (KIRC), ovarian serous cystadenocarcinoma (OV), rectum adenocarcinoma (READ), SKCM, stomach adenocarcinoma (STAD), and UCS. Here, TAP1 is linked to bladder transitional cell carcinoma.