PECAM1 and intrahepatic cholangiocarcinoma: Before induced differentiation, the unsorted cell population from a majority of patients contained 17±2.5% CD31+ cells as measured by ICC (Figure 8A.a, and 8B, n = 5 patients) and 21.7±2.6% CD31+ cells as measured by flow cytometry (n = 3 patients, data not shown).