{"id":"ca-19-9","name":"CA 19-9 (Cancer Antigen 19-9)","shortName":"CA 19-9","aliases":["CA 19-9","CA19-9","Cancer Antigen 19-9","CA 19-9, Serum","Carbohydrate antigen 19-9","Cancer Antigen (CA) 19-9","GI Cancer Antigen","Carbohydrate Ag 19-9, S","CA-19-9","CA19.9","Cancer Ag 19-9"],"abbreviations":["CA 19-9","CA19-9"],"loinc":[{"code":"24108-3","primary":true},{"code":"83084-4","primary":false}],"specimen":"serum","units":[{"ucum":"U/mL","display":"U/mL"},{"ucum":"kU/L","display":"kU/L"}],"referenceRanges":[{"population":"Adults","low":0,"high":35,"unit":"U/mL","unitDisplay":"U/mL","note":"Labcorp prints 0 to 35 U/mL and Mayo Clinic Laboratories prints under 35 U/mL. Some labs and studies use 37 U/mL. A value in range can falsely reassure in people who can't make CA 19-9 (Lewis-negative). Use the range printed on the lab report.","sources":[{"title":"Carbohydrate Antigen (CA) 19-9 (test 002261)","url":"https://www.labcorp.com/tests/002261/carbohydrate-antigen-ca-19-9","publisher":"Labcorp"},{"title":"CA19 - Overview: Carbohydrate Antigen 19-9 (CA 19-9), Serum","url":"https://www.mayocliniclabs.com/test-catalog/overview/9288","publisher":"Mayo Clinic Laboratories"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"A sugar-and-protein molecule that some digestive-system cancers release. Many harmless bile duct, liver and pancreas conditions raise it too.","url":"https://bloodtesttracker.com/markers/ca-19-9","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}