Caspase-8–deficient IECs are hypersensitive to SMAC mimetic–induced necroptosis. (A and B) RIP3 protein in colon tissues from the indicated mice was detected with immunoblots (β-actin served as a loading control; A) and immunostaining (B). Cell nuclei were counterstained with Hoechst 33342. Bars, 75 µm. (C–E) WT, Casp8ΔIEC, Casp8ΔIEC × Tnfr1−/−, and Casp8ΔIEC × Rip3−/− mice were treated with a single dose of 50 mg/kg LCL161 (oral). For histological analyses, tissues were collected 24 h after LCL161 administration. (C) Representative pictures of the small intestine and colon tissues from the indicated mice subjected to staining with H&E (left; bars, 75 µm), β-catenin (middle), and TUNEL (right). Cell nuclei were counterstained with Hoechst 33342. (D) Kaplan–Meier survival curve. Group sizes: n > 5. (E) Representative pictures of small intestine and colon tissue from the indicated mice stained with H&E (left; bars, 75 µm). Results from at least three biological replicates are presented unless otherwise specified. (D and E) Data derived from two independent animal experiments are shown.