However, objective response rates of only 19% and 37% have been reported for patients with high PD-L1-expressing (≥10% cells) squamous and non-squamous NSCLC, respectively, following nivolumab treatment.2 3 Several case reports have described a phenomenon known as pseudoprogression, in which initial tumor progression is followed by shrinkage during continuous treatment with immune-checkpoint inhibitors5 6; notably, this is not seen with cytotoxic drugs or other targeted agents. This evidence concerns the gene CD274 and non-small cell lung carcinoma.