TP63 and Patent ductus arteriosus: While a basal level of IL-1 is expressed in PDA tumor cells that lack p63 expression (Biffi et al., 2019; Tjomsland et al., 2011; Zhang et al., 2018), a key finding in our current study is in demonstrating that a striking heterogeneity exists in IL-1 expression in the human disease, with the highest levels being found in p63-expressing squamous-subtype tumors.