BCR and myeloproliferative disorder: The aforementioned instrument, termed the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS) or simply MPN-10, is an abbreviated symptom burden scoring system particularly developed to assess QoL in individuals living with classical BCR::ABL1-negative MPNs, i.e., PV, ET, primary (PMF) or secondary myelofibrosis (SMF), and MPN-unclassifiable (MPNu) [6].