However, single-agent immunotherapy in the first-line setting is limited to the small subset of NSCLC patients whose tumors have a PD-L1 tumor proportion score of 50% or more ‘without EGFR or ALK genomic tumor aberrations’, for which pembrolizumab is proven to be superior in terms of efficacy and safety profiles [8]. The gene discussed is ALK; the disease is non-small cell lung carcinoma.