TGFB1 and neoplasm: Of the two PDAC epithelial cell lineages,6–9 the basal-like/squamous phenotype displays a more aggressive behaviour and it is enriched in post-treatment tumours as well as in metastases.7 We found that both cell-intrinsic (eg, biallelic inactivation of p53) and cell extrinsic (eg, TGF-β1) factors promoting the basal-like/squamous subtype induce expression of SEMA3A in PDAC cells.