CD274 and non-small cell lung carcinoma: A recent prospective study evaluated CTC PD-L1 expression in patients with recurrent or metastatic NSCLC prior to and after initiation of ICI therapy and found that increased expression of CTC PD-L1 from prior treatment to after treatment was associated with better PFS and OS, which may potentially allow for determination of which patients may benefit from further ICI therapy [103].