NF-Ya–deficient BM chimeric mice die with severely reduced complete blood counts. (A) PB from one cohort of control (gray) and ko (black) BM chimeric mice 1, 3, 8, 11, 22, and 50 days after the first pIpC injection was isolated and counted (n ≥ 4 for every time point). (B) Survival curve of control (gray) and ko BM chimeric mice (black) of 2 cohorts not used in any other experiment. (C) DNA from control and ko BM chimeric mice from panel A was isolated from PB 7 days after the first pIpC injection and tested quantitatively for the presence of the NF-Ya ko allele (NF-Ya floxed allele after cre recombination; n ≥ 4); **P < .01.