AHR and myeloproliferative disorder: In previous investigations, it was observed that lack of AHR in the “Bradfield” KO mice (B6.129-Ahrtm1Bra/J), in which there is a deletion of exon 2 in the Ahr gene [7], alters the gene expression profile of the most primitive progenitors belonging to LTHSCs [12] and also leads to altered expression of genes associated with myeloproliferative disorders in aging mice as well as shorter lifespans [13].