In patients with breast cancer, ovarian cancer, gastric cancer, NSCLC, BLCA, READ, SARC, UCEC, MESO, KIRC, and SKCM, higher expression of BTN3A1 was associated with better prognosis; but in patients with TGCT and LGG, higher expression of BTN3A1 was associated with worse prognosis. Here, BTN3A1 is linked to bladder transitional cell carcinoma.