CHAF1A and neoplasm: Our in vitro combination regimen (RA, 0.3–40 μм; DFMO, 0.2–5.4 mм) is close to the plasma concentration measured in patients receiving 13‐cis‐RA (5–11 μм)[13, 70] and DFMO (0.05–0.17 mм).[48] Importantly, the combination therapy DFMO+RA effectively blocks polyamine metabolism, exerts greater in vivo anti‐tumor activity compared to single therapies and closely recapitulates the effects of the combination CHAF1A genetic depletion+RA, suggesting that targeting CHAF1A or CHAF1A‐induced polyamine metabolism enhances RA activity.