The development of efficient and reliable laboratory test is critical in the selection of patients likely to respond to these targeted agents. Currently, the current gold standard for testing for EML4-ALK translocation is fluorescent in situ hybridization (FISH) for selecting patients for ALK-tyrosine kinase inhibitors (TKI) therapy according to the United States Food and Drug Administration (FDA). But, an important aspect is the amount of available tumor present in a determined sample, given the labor-intensive nature and cost of the test, there has been interest in validating other screening and diagnostic tools. Recent evidence suggests that ALK Immunohistochemistry (IHC) instruments globally protocols, can be very effective in the detection of ALK rearrangement in NSCLC (ALK+) tumors expressing the fusion ALK protein.