There was no evidence of a correlation between C4 and total bile acids in healthy controls (Spearman’s rank-order correlation rs = 0.01), and in blood from patients with PSC, there was a tendency of a tapering in the increase in C4 at total bile acid concentrations within the normal range of healthy controls (Fig. 1C, top-right panel). This evidence concerns the gene C4A and pancreatic serous cystadenoma.