Further qRT-PCR of 14 paired ICC and adjacent non-tumor tissue samples indicated that 13 out of 14 pairs of samples had higher levels of CyclinD1 expression and lower levels of Dicer expression with a Pearson correlation coefficient of − 0.964 (P < 0.01, Fig. 1c). This evidence concerns the gene DICER1 and intrahepatic cholangiocarcinoma.