Blood is a peer-reviewed medical journal published by the American Society of Hematology. It was established by William Dameshek in 1946. The journal changed from semimonthly (24 times annually) to weekly publication at the start of 2009. It covers clinical and basic research in all areas of hematology, including disorders of leukocytes, both benign and malignant, erythrocytes, platelets, hemostatic mechanisms, vascular biology, immunology, and hematologic oncology.