Given the fact that a previous GWAS demonstrated an association between PV and variants in the vicinity of the ST18 gene locus [8], we aimed at characterizing this risk region and therefore performed targeted deep sequencing of the ST18 locus in 16 Jewish PV patients, initially comparing the sequencing results to the 1000 Genomes Project (1000GP) data (http://www.1000genomes.org). Here, ST18 is linked to acquired polycythemia vera.