<B>WHO Classification System</B> 
 In 1999, the World Health Organization, or WHO, published a new classification system improving the FAB classification system. This system was then updated in 2008. Its goal was to be more specific than the FAB in describing subtypes and in predicting what will happen to patients with each subtype. The system is based on patient data from around the world and on the most up-to-date knowledge of MDS.