PD-L1 rs2890658 Polymorphism Increases Risk for Non-Small-Cell Lung Cancer in Northern China Population Based on Experimental Data and Meta-Analysis

Table 3

Main characteristics of all case-control studies included in meta-analysis.

Literature	Ethnics (Country)	Genotyping methods	Source of control	Sample size	HWE conformity	NOS
Chen et al.	Asian (China)	PCR-RFLP	PB	293/293	Yes	8
Ma et al.	Asian (China)	PCR-RFLP	PB	528/600	Yes	9
Cheng et al.	Asian (China)	PCR-RFLP	PB	288/300	Yes	8
Zhao et al.	Asian (China)	PCR-RFLP	PB	281/251	Yes	8

PB, population-based; HWE: Hardy–Weinberg equilibrium; RFLP, restricted fragment length polymorphism; NOS, Newcastle-Ottawa score.