The transgene is constructed with a mouse promoter and a mutated human cDNA, using the pSP65-H2K-i-LTR vector. The human cDNA is for the type 1 mutation (del52) that has a 52 bp deletion in exon 9, commonly found in essential thrombocythemia (ET) patients. Two copies of the transgene were found to have inserted head-to-head into intron 5 of the host gene. RT-PCR experiments confirmed expression from the transgene. (J:241724)