SFRP1 and intrahepatic cholangiocarcinoma: Further quantitative RT–PCR of 20 paired ICC and adjacent nontumor tissue samples revealed that 18 of the 20 pairs of samples had higher levels of H2A.Z expression and lower levels of SFRP1 expression in the ICC tissues, with a Pearson correlation coefficient of -0.6776 (**P = 0.001, Fig. 1C).