Rowley published her seminal Nature paper identifying the translocation forming the Philadelphia chromosome in chronic myelogenous leukemia.
On June 8, 1973, Janet Rowley published her groundbreaking paper, "A new consistent chromosomal abnormality in chronic myelogenous leukemia identified by quinacrine fluorescence and Giemsa staining," in the prestigious journal Nature.
Working largely from a makeshift lab in her home using a borrowed fluorescence microscope, Rowley applied newly developed chromosome banding techniques to blood samples from leukemia patients. This allowed her to see, for the first time with clarity, that the Philadelphia chromosome—first identified in 1960 as an abnormally short chromosome 22—was not simply a deletion, but the result of a reciprocal translocation between chromosomes 9 and 22.
This discovery was revolutionary because it proved that specific, recurring genetic rearrangements, rather than random chromosomal damage, were the direct cause of certain cancers. It shifted the entire paradigm of cancer research toward genetics and molecular biology.
The identification of the t(9;22) translocation eventually led to the identification of the BCR-ABL fusion gene, which became the target of the drug imatinib (Gleevec), one of the first successful targeted cancer therapies. Rowley's meticulous, patient work is often cited as one of the most important single discoveries in the history of cancer research, transforming chronic myelogenous leukemia from a fatal diagnosis into a manageable chronic condition for many patients.