Table 3. Tumor proportion scores of primary tumors by Dako PD-L1 IHC 22C3 PharmDx, and Dako PD-L1 IHC 28-8 PharmDx assays.

Dako 22C3	Dako 28-8 (%)
	No	Low	High
No expression (<1%)	5 (14.3)	2 (5.7)	0 (0)
Low expression (1–49%)	3 (8.6)	17 (48.6)	2 (5.7)
High expression (>50%)	0 (0)	2 (5.7)	4 (11.4)

Pearson’s chi-square test: P<0.001.