Influence of CD1d on hematopoietic progenitor cells in C57B1/6 and Balb/c mice. Absolute numbers of immature subsets of CFU-GM, BFU-E, and CFU-GEMM in BM (femur) and spleens of WT littermate controls (WT = +/+) and CD1d^−/− mice on a C57Bl/6 (A) and Balb/c (B) background. Cycling status (percentage of cells in the S phase) of immature subsets of CFU-GM, BFU-E, and CFU-GEMM in the BM (femur) and spleen in WT and CD1d^−/− mice on a C57Bl/6 (C) and Balb/c (D) background. Results are expressed as means ± 1SEM for 17 mice each from a total of 4 experiments for C57Bl/6 mice (A and C) and 8 mice each from a total of 2 experiments for Balb/c mice (B and D). Significance values of CD1d^−/− compared with WT cells are shown.