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IASLC ATLAS OF ALK TESTING IN LUNG CANCER
guidelines. Furthermore, FISH may rarely produce equivocal or even erroneous results. As any other clinical test, ALK break-apart FISH has unique strengths and limitations and should be used within an appropriate diagnostic context. It is also strongly recommended that each laboratory perform internal validation studies using known controls before this method is introduced as a routine test. In addition, laboratories should participate in periodic slide exchange programs with other accredited clinical laboratories or in proficiency testing surveys provided by approved vendors.