To validate the altered transcriptomic profile of IL-18 on the protein level in MPN, we used an ELISA assay to measure IL-18 levels in the peripheral plasma of a healthy cohort and four cohorts of patients with MPN stratified by their fibrosis grade of MF (grades 0, 1, 2, 3). This evidence concerns the gene IL18 and myeloproliferative neoplasm.