PDGFRA and intrahepatic cholangiocarcinoma: These data are consistent with previous immunohistochemical studies demonstrating a close association between ICC-IM and nitrergic, VIPergic, cholinergic and adrenergic nerve fibers (Beckett et al., 2005, Blair et al., 2012, Cobine et al., 2011, Cobine et al., 2018, Keef et al., 2013, Kurahashi et al., 2012) and between PDGFRα+ cells and nNOS+ nerves in the mouse IAS, Cynomolgus monkey LES and IAS and human esophagus (Blair et al., 2012, Chen et al., 2013, Cobine et al., 2010, Cobine et al., 2011).