C > G transversions were noted in several genes known to be relevant for T-ALL, including Stat5b, Ntrk2, and Trp53. In addition, in vitro treatment of both murine and human cell lines with 5AZA using a single cell GEMINI assay led to a clear and dramatic increase in C > G transversions. The gene discussed is STAT5B; the disease is acute lymphoblastic leukemia.