Skewed T-cell development toward CD8 lineage in SOCS1-deficient mice arises from an IFNγ-independent, T-cell intrinsic defect. (A) SOCS1-deficient FTOCs recapitulate T-cell developmental skewing toward the CD8 lineage. FTOCs were established from day 14.5 SOCS1^-/- embryos and their littermate controls. Single-cell suspensions were prepared on indicated days and analyzed for the frequency of DN, DP, CD4⁺, and CD8⁺ cells. Results shown are representative of at least 6 thymi per group from 2 experiments. (B) Maturation of SOCS1-deficient DN precursors in Rag1^-/- thymus is skewed toward the CD8 lineage. DN cells sorted from 4-week-old SOCS1^-/- thymi and their littermate controls were injected into Rag1^-/- thymi, and the frequencies of DN, DP, CD4⁺, and CD8⁺ cells were estimated after 14 days. Data shown are representative of 3 animals per group.