The DNA methylation microarray approach in the NCI60 panel of cancer cell lines revealed SLFN11 methylation (higher than 0.5) in 25% (15 of 59) of cell lines, whereas for the remaining 75% (44 of 59) of cell lines the 5′-end CpG island remained unmethylated (lower than 0.5) (Figure 1B). The gene discussed is SLFN11; the disease is cancer.