Table 1. Characteristics of studies included in this meta-analysis.

Study	Ethnicity	Screening of controls	Genotype method	Case			Control			Confounding factors adjusted or stratified	Cys(%)	HWE(P value)
				Male (%)	Age(mean, sd)	Cys-Cys/Cys-Ser/Ser-Ser	Male (%)	Age(mean, sd)	Cys-Cys/Cys-Ser/Ser-Ser
Zhu, 2004	Chinese	Hospital	PCR-RFLP	NA	NA	57/99/37	NA	NA	50/62/22	Sex, age, smoking, drinking, HBV, HCV, family history of HCC	60.4	>0.7
Sakamoto, 2006	Japanese	Hospital	PCR-CTPP	67%	69	43/110/56	65%	61	79/123/73	Sex, age, smoking, drinking, HBV, HCV	51.1	>0.05
		CLD†					54%	61	100/176/105		49.3	>0.1
Zhang, 2006‡	Chinese	Hospital	Sequencing	84%	49.9±18.0	18/38/30	82%	49.9±17.0	13/35/42	HBV	33.9	>0.2
Wang, 2008	Chinese	HBVcomparable§	Taqman	84%	50.2±11.3	52/92/31	matched	matched	34/58/27	Sex, age, smoking, drinking, HBV, HCV, family history of HCC	52.9	>0.8
Ji, 2011	Chinese	Hospital	Taqman	79%	47.8±11.1	103/40/357	74%	48.9±11.2	29/51/427	Drinking, HBV	10.7	<0.001
Tang, 2011	Chinese	Healthy	PCR-RFLP	100%	matched	47/82/21	100%	matched	56/72/22	None	61.3	>0.8
Jung, 2012*	Korean	HBV	SNPstream	82%	53.3±8.3	207/343/156	83%	52.6	116/181/89	Sex, age	53.3	>0.2
Yuan, 2012	Chinese	HBVcomparable§	PCR-RFLP	76%	52.1±7.6	66/217/67	75%	51.1±9.2	50/206/144	Sex, age, drinking, HBV, family history of HCC	38.3	>0.05

HWE, Hardy-Weinberg equilibrium; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; HBV, hepatitis B virus; HCV, hepatitis C virus; HCC, hepatocellular carcinoma; CLD, chronic liver diseases; CTPP, confronting two-pair primers; NA, not available.

^†In this control group, 97% of subjects were infected with HCV and/or HBV.

^‡Sex and age information was from 91 case subjects and 91 control subjects.

^§Case group and control group had comparable background of HBV infection.

^*Sex and age information was from 708 case subjects and 388 control subjects.