The proportion of core binding factor leukemia (CBF) leukemia, characterized by the presence of either t(8;21)(q22;q22) or inv(16)(p13.1q22) or t(16;16)(p13.1;q22) was significantly higher in adolescents (15 of 39, 38%) (p = 0.01). The gene discussed is CEBPZ; the disease is leukemia.