CD81 and cancer: Proteomic data from the urinary exosomes of 261 cancer patients (bladder cancer, prostate cancer, renal cancer, lung cancer, cervical cancer, colorectal cancer, esophageal, and gastric cancer) and 124 healthy controls identified 17 proteins (CD59, CDC42, ITM2B, CD81, PEBP1, VAT1, MYO1D, RAC1, DPP4, RAN, CAPG, PPIA, FOLR1, ANXA3, APOD, ANXA4, and AQP2) important for cancer diagnosis.