Variants on a theme: a biomarker of crizotinib response in ALK-positive non-small cell lung cancer?

Anaplastic lymphoma kinase (ALK) gene rearrangements are found in approximately 5% of non-small cell lung carcinoma patients and confer sensitivity to ALK inhibitors such as crizotinib. The particular ALK fusion expressed may have an impact on protein stability and sensitivity to crizotinib, and this may underlie the heterogeneity in responses observed in the clinic.