Figure 1

Lung cancer cases stained with hematoxylin–eosin and different PD-L1 assays. Original magnifications × 200. (a–f) A case positive in all assays. (g–l,m–r) Two different cases with variation in staining properties between assays. (s–x) A case with unspecific cytoplasmic staining in 28-8, SP263, and 28-8A (Abcam) PD-L1 assays.