The IHC test approved by the United States Federal Drug Administration (FDA) for ALK testing is the VENTANA ALK (D5F3) CDx Assay (Ventana Medical Systems, Tucson, AZ, US), intended for qualitative detection of ALK in formalin-fixed paraffin embedded (FFPE) NSCLC tissue (Fig. 2b) stained using a BenchMark XT or BenchMark ULTRA automated staining instrument. The gene discussed is ALK; the disease is non-small cell lung carcinoma.