ERBB2 and cholangiocarcinoma: Those inactive in WD-PDXs, and with potential to be restored by the addition of MSCs, include kinases such as ERBB3, EGFR, ERBB2 and MET, the activation of which is associated with growth promotion (Jin, 2020; Yoshikawa et al., 2008; Dai et al., 2012), with ERBB2, EGFR and MET associated with the proliferative molecular subclass of CCA (Sia et al., 2013).