PDCD1 and non-small cell lung carcinoma: Interestingly, CD274 (and, accordingly, PD-L1 IHC) expression was not significantly different between stage III and IV cancers, nor was the expression of PDCD1 or TIGIT. Despite these findings and the substantial risk associated with inoperable stage III NSCLC, the recent breakthrough designation for dual blockade of TIGIT/PD-L1 was restricted to stage IV patients [25].