Runx1^{tm2.1(cre/Esr1*)Ims}

A targeting vector was composed of the sequence for a tamoxifen-inducible cre recombinase (flanked by two mutated estrogen receptors, MerCreMer) with the Engrailed-2 splice acceptor (En2SA) sequence preceding the coding region and a transcription STOP sequence followed the cre/Esr1*. A floxed neo selection cassette followed the STOP. Insertion of the En2SA sequence prevents splicing of the STOP out and disrupted Runx1 expression from both the proximal P2 and distal P1 promoters. The neo was subsequently deleted from the allele. (J:182232)