SMAD4 and Patent ductus arteriosus: We assessed the genetic status of three of the most commonly mutated genes in human PDA and drivers of PDA in various GEMMs (p53, p16Ink4, and Smad4) in primary AKC tumors and three different low-passage cell lines (AKC8, AKC14, and AKC17) derived from different AKC tumors.