A clonal hematopoietic stem cell disorder, characterized by proliferation in the bone marrow of one or more of the myeloid (i.e., granulocytic, erythroid, megakaryocytic, and mast cell) lineages. It is primarily a neoplasm of adults. (WHO 2008) Chronic Myeloproliferative Disease is an NCI Cancer Therapeutic Evaluation Program (CTEP) Simplified Disease Classification (SDC) category used to organize cancer-related disease coding that harmonizes with and supports reporting based on the global standard Medical Dictionary for Drug Regulatory Reporting (MedDRA) terminology.