In a phase 2 trial evaluating pembrolizumab in patients with NSCLC or melanoma and untreated BrMs (5–20 mm in size, not previously treated or with progression after prior radiotherapy), intracranial responses were observed in 29.7% of the cohort with at least 1% PD-L1 expression (n = 37); no intracranial responses occurred in the patients with less than 1% or unevaluable PD-L1 expression (n = 5) [125]. Here, CD274 is linked to melanoma.