Circulating free fatty acids increase from ≈0.2 to 0.5 mm by 6 h post‐PHx, and whole‐body fat mass drops by ≈20% within 24 h.[2, 31, 32] Lipodystrophic models, such as fld and Seipin−/− mice, exhibit reduced transient steatosis and impaired regeneration.[33, 34] Adipose‐specific deletion of Lipe (encoding hormone‐sensitive lipase) halves hepatic TG accumulation and delays regeneration.[35] In contrast, liver‐specific deletion of Fasn does not alter steatosis or liver regrowth,[31] indicating that de novo lipogenesis is not a major lipid source in the initial regenerative response. The gene discussed is FASN; the disease is steatosis.