TP53 and myeloproliferative disorder: As TP53-heterozygous mutant HSPCs represent the direct genetic ancestors of TP53 ‘multihit’ LSCs, we compared gene expression of heterozygous TP53-mutant HSPC from pre-TP53-sAML (n = 296) to CP TP53-MPN (n = 273; Fig. 4b, blue box) to identify putative mediators of transformation.