BMF phenotype in Tak1^−/− mice is partially prevented by inactivation of TNF-α signaling. Femurs, tibias, spleens, and PB of mutant mice with indicated genotypes were collected on day 8 after induction of Tak1 gene deletion. (A) H&E-stained BM sections from indicated genotypes of mice (20 × 0.7 air). Bar represents 100 μm in length. (B-C) Numbers of MNCs from 2 hind legs (B) and spleen (C) of each mouse were counted. (D-E) WBC counts and plt (platelet) numbers in PB of mice were analyzed by CBC. (F) The percentage of reticulocytes was examined in PB by methylene blue staining. (G) Concentration of IFN-γ in PB of mice was measured by ELISA. Data are the average of 4 mice from each genotype. **Significant difference compared with WT control mice (P < .01). $$Significant increase compared with Tak1^−/− mice (P < .01).