However, dominant expression of P2ry1 is found in PDGFRα+ interstitial cells, not SMCs or ICC, and purinergic inhibitory effects are mediated through PDGFRα+ cells (Kurahashi et al., 2011, 2014; Baker et al., 2013, 2015). This evidence concerns the gene PDGFRA and intrahepatic cholangiocarcinoma.