Typ515 (W515) mutations in the protein MPL are one of the key driver mutations promoting BCR-ABL-negative myeloproliferative neoplasms (MPNs), but, to our knowledge, their effects on hematopoietic stem cells (HSCs) and MPN-related hematological abnormalities have not been studied in physiological contexts. This evidence concerns the gene ABL1 and myeloproliferative neoplasm.