An example of duplex sequencing of a T315I mutation. Duplex sequencing eliminates background “noise” found in NGS. Top, sequencing of a CML patient with a known T315I ABL tyrosine kinase domain mutation. NGS found background mutations in almost all base pair regions at the 1% level. Bottom, with duplex sequencing, the background technical artifacts are eliminated, with only the true mutation remaining. Figure reprinted with courtesy from Schmitt et al.⁵⁹