The Cdk4 R24C allele rescues defective progenitor potential in Cdk6 R31C mice. (A) Analysis of the donor cells’ contribution within the LSK fraction 16 weeks after bone marrow transplantation (n = 5 for wild-type, Cdk4^R/R or Cdk6^R/R single mutants; n = 4 double-mutant mice). (B) Analysis of the donor contribution to individual lineages in bone marrow, spleen, and peripheral blood (n = 5 for wild-type, Cdk4^R/R or Cdk6^R/R single mutants; n = 4 double-mutant mice). (C) Analysis of bone marrow repopulation after 5-FU treatment. Flow cytometry analysis of hematopoietic progenitors (LSK cells) 7 days after treatment with 5-FU (n = 3 Cdk4^R/R or Cdk6^R/R single mutants; n = 6 wild-type mice; n = 7 double-mutant mice). Representative hematoxylin and eosin images of the bone marrow from untreated mice or mice treated with 5-FU mice are included. DMSO, dimethylsulfoxide. Scale bars, 50 μm. *P < .05; **P < .01; ***P < .001. 1-way ANOVA including Bonferroni’s multiple comparison test.