JAK-STAT pathway activation leads to an enhanced activity of the promoter of CD274 (PDL1) coding programmed death-1 receptor ligand (PD-L1), increased PD-L1 level and the immune escape of myeloproliferative neoplasms (MPN) cells.
It has been postulated that the bone marrow failure, bone marrow myeloid metaplasia, and changes in the molecular characteristics of the malignant clone (s) during MPN outcome may in uence the JAK2 and PDL1 gene expression. Aim: to evaluate the PDL1 mRNA and JAK2 mRNA level in molecularly de ned essential thrombocythaemia (ET) patients (pts) during disease progression to post-ET-myelo brosis (post-ET-MF).