TP63 and Patent ductus arteriosus: While the mechanisms that induce p63 expression in PDA remain unclear, it has been shown in mice that inactivation of the tumor suppressor Kdm6a or over-expression of Myc can predispose pancreatic tumors to express squamous markers, albeit with partial penetrance (Andricovich et al., 2018; Hayashi et al., 2020; Witkiewicz et al., 2015).