Reference intervals for carcinoembryonic antigen (CEA), CA125, MUC1, Alfa‐foeto‐protein (AFP), neuron‐specific enolase (NSE) and CA19.9 from the NORIP study

For AFP, CA125 and CA19.9, the reference levels obtained were close to previously reported reference ranges. Smoking and age were confirmed as covariates for CEA. The associations between MUC1 with age and BMI and between NSE and smoking have not been reported previously.