Biodistribution experiments in F9 tumor-bearing mice by using radioiodinated L19mTNFα and TN11mTNFα (A) The %ID/g of tumor (⋄) and blood (□) at different times from intravenous injection of ¹²⁵IL19mTNFα (mean ± SD). (B) The %ID/g of tumor (⋄) and blood (□) at different times after intravenous injection of ¹²⁵I-TN11mTNFα (mean ± SD). (C) Tumor-to-blood ratio of the %ID/g after injection of ¹²⁵I-L19mTNFα (⋄), ¹²⁵I-TN11mTNFα (□) and ¹²⁵I-L19 (scFv)₂ (○). (D) Microautoradiographies of F9 tumor (i), liver (ii), kidney (iii), and lung (iv) 6 hours after intravenous injection of ¹²⁵IL19mTNFα. L19mTNFα accumulates selectively in the F9 tumor vasculature. Bars = 200 μm (i), and 50 μm (ii-iv).