EGF and hepatocellular carcinoma: When stratifying by study quality, the results showed that EGF +61A/G polymorphism was associated with an increased HCC risk both in high-quality studies (G vs. A: OR = 1.178, P < 0.001, 95% CI: 1.077-1.289, I2 = 0.0%, Pheterogeneity = 0.539) and in low-quality studies (G vs. A: OR = 1.740, P = 0.010, 95% CI: 1.144-2.648, I2 = 87.1%, Pheterogeneity < 0.001).