There was only one gene (PHLDA1) in common between the 36-gene signature and the Quasimesenchymal subtype (QM-PDA) of Collisson et al. Upon expanding the 36-gene signature to its candidate prognostic gene list (225 genes, hereafter referred to as PDAC-225) (Additional file 2: Table S2), only three genes were shared between PDAC-225 and Donahue et al. (Figure 3B). Here, PHLDA1 is linked to Patent ductus arteriosus.