According to the 2022 World Health Organization (WHO) classification for hematopoietic malignancies [1], major categories of BCR::ABL1-negative myeloproliferative neoplasms (MPN) include polycythaemia vera (PV), essential thrombocythaemia (ET), and primary myelofibrosis (PMF). The gene discussed is BCR; the disease is essential thrombocythemia.