We found that mRNA expression of NT5E, TGFB1, FN1, and ITGA5 is enriched in aggressive subtype of PDA (squamous/basal-like) (Figs 3e,f, S5a,c,e,g,i,j), and that PDA having high expression of those genes showed poor prognosis in the ICGC and/or in the TGCA cohorts (Figs 3g, S5b,d,f,h,k). Here, ITGA5 is linked to Patent ductus arteriosus.