Variation in CAFC day 35 frequency and Ezh2 expression levels in BXD strains. (A) Variation in HSC frequency (CAFC d35/10⁵ BM cells) in BXD recombinant inbred mice is associated with a QTL mapping to chromosome 18. Data can be retrieved from www.genenetwork.org.^41,48  (B) Ezh2 transcript levels were measured in LSK cells isolated from the BM of 30 BXD strains, using Affymetrix gene chips. (C) Variation in Ezh2 expression in LSK cells isolated from BXD mice is regulated by a QTL mapping to chromosome 18. (D). Average Ezh2 expression levels (+ 1 SEM) in BXD recombinant inbred mice segregated according to the presence of the B6 (▪) or D2 () allele for marker D18Mit83.