Table 3. Selected studies of ALK+ NSCLC and PD-L1 expression.

Total patient samples	PD-L1 detection method	Scoring method	Number of samples PD-L1 positive	Reference
10	PD-L1 antibody ab58810 (Abcam)	Staining intensity: 0 negative or trace, 1 weak, 2 moderate and 3 high. Positive samples contained a staining intensity ≥2 in more than 5% of tumor cells	6	(15)
19	PD-L1 antibody (clone E1L3N, Cell Signaling Technology)	PD-L1 positivity: membranous ± cytoplasmic staining of tumor cells of any intensity using cutoffs of ≥1%, ≥5%, and ≥50% tumor cells	PD-L1 ≥5%: 9; PD-L1 ≥50%: 5	(1)
9	22C3 pharmDx assay (Agilent Technologies)	PD-L1 tumor proportion score was calculated as the percentage of at least 100 viable tumor cells with complete or partial membrane staining	PD-L1 TPS 1–49%: 3; PD-L1 TPS ≥50%: 2	(16)

ALK, anaplastic lymphoma kinase; NSCLC, non-small cell lung cancer; PD-L1, programmed cell death 1 ligand 1; TPS, tumor proportion score.