Development of Classification of Acute Leukemia 1976 French-American-British(FAB) Cooperative Group proposed classification of acute leukemia based on morphologic criteria that were subsequently refined in 1981 and 1985 1986 Morphologic, immunologic and cytogenetic (MIC) classification was introduced. Recognition of importance of cytogenetics in the diagnosis and treatment of acute leukemia 2001 World Health Organization(WHO) classification recognized new clinically relevant molecular genetic lesionsDevelopment of Classification of Acute Leukemia 1976 French-American-British (FAB) Cooperative Group proposed classification of acute leukemia based on morphologic criteria that were subsequently refined in 1981 and 1985 1986 Morphologic, immunologic and cytogenetic (MIC) classification was introduced. Recognition of importance of cytogenetics in the diagnosis and treatment of acute leukemia 2001 World Health Organization (WHO) classification recognized new clinically relevant molecular genetic lesions