Shi and coworkers applied the PRISM targeted proteomics to quantitate AGR2 in human urine at serum at concentrations of approximately 130 pg/ml and 10 pg per 100 ug of total protein mass in urine, respectively, and found in a proof‐of‐concept study of 37 urine samples that AGR2/PSA concentration ratios can distinguish noncancer and cancer 85. Here, AGR2 is linked to cancer.