In contrast, it was only observed in 13/30 (43%) patients with PDGFRB, FGFR1 or JAK2 fusion genes Absence of eosinophilia was restricted to 9/30 (30%) patients with PDGFRB, FGFR1 and JAK2 fusion genes (Table 5). This evidence concerns the gene JAK2 and Increased total eosinophil count.