World Chronic Myeloid Leukemia Day, observed worldwide every September 22, aims to spread information about chronic myeloid leukemia (CML) and highlight the challenges faced by those affected by the disease. The day was first observed on September 22, 2008, originally as CML Awareness Day, and became an international observance in 2002. The date is significant as it symbolizes the Philadelphia chromosome, a genetic abnormality associated with CML, resulting from a translocation between chromosomes 9 and 22. CML is characterized by the uncontrolled growth of myeloid cells in the bone marrow and blood, and it has three phases: chronic, accelerated, and blast crisis. Typical treatments include bone marrow transplantation and tyrosine kinase inhibitors. The observance serves to emphasize the importance of finding a cure for this type of leukemia.