The NCI-60 cell lines also show a wide variety of basal % γ-H2AX values (Fig 5A, right hand panel), from a low of 0.2% found in NHFs and the breast cancer cell line MCF7 to greater than 4% observed in the acute myeloid leukemia cell line HL-60(TB). The gene discussed is H2AX; the disease is breast carcinoma.