In this study, we developed a quantitative real-time reverse transcriptase PCR assay to measure ALK rearrangement status in cancer patients at three levels: (1) expression of the non-coding RNA sweyjawbu; (2) comparison of the expression of the 5′ and 3′ regions of the ALK transcript; and (3) expression of known ALK hybrid subtype variants. This evidence concerns the gene ALK and cancer.