CD274 and lung carcinoma: Similar to ALK and ROS1 fusions, RET-rearranged tumors exhibit variable PD-L1 expression; however, they are among the most immunologically ‘cold’ lung cancers, characterized by a median TMB of 1.75 mutations/MB, low neoantigen production, and intrinsic resistance to immunostimulatory therapies [99], seemingly independent of PD-L1 expression alone [100].