PDGFRA and intrahepatic cholangiocarcinoma: In order to examine whether the inhibitory effect of progesterone on the contraction of colonic smooth muscle is caused by the regulation of PDGFRα+ cells and ICC, we first added apamin to block the SK3 channel on PDGFRα+ cells and NPPB to block the ANO1 channel on the ICC, and found that the contraction of colonic smooth muscle in both groups was obviously inhibited; while in the presence of apamin and NPPB, progesterone did not inhibit the contraction of smooth muscle in both groups (Fig. 2H and I; P < 0.05; n = 7).