G6PD and chronic myelogenous leukemia, BCR-ABL1 positive: Developing an interest in human genetics, he pursued a 2-year fellowship in Motulsky’s division of medical genetics.61 Fialkow worked in the Gartler laboratory, applying Linder’s and Gartler’s technique of using G6PD isoenzyme expression to study the cell of origin of chronic myelogenous leukemia.