BTLA and urinary bladder cancer: Another inhibitory receptor, B‐ and T‐lymphocyte attenuator (BTLA), was found to be upregulated on DC from tumor tissue (as compared to those from normal adjacent tissue) of bladder cancer patients, and in vitro studies demonstrated that the BTLA ligand HVEM suppressed proinflammatory cytokine secretion by both cDC1 and pDC obtained from PBMC of healthy donors.62