MUC5AC and neoplasm: In the absence of a method to quantify mucins in blood, carbohydrate antigen CA19-9, a widely used tumour marker for pancreatic cancer, could serve as a surrogate marker, as it binds to apomucins, including MUC1, MUC5AC and MUC16.47 Woei-A-Jin et al.48 reported that the plasma levels of CA19-9 correlated with increased stage, shortened survival and severity of VTE in 79 patients with pancreatic cancer.