To date, more than 70 different TK fusion genes with recurrent involvement of at least six TK (PDGFRA, PDGFRB, FGFR1, JAK2, ABL1, FLT3) have been identified in clinically and morphologically distinct MLN with or without eosinophilia [4]. The gene discussed is FGFR1; the disease is Increased total eosinophil count.