HYKK and lung cancer: Grouping studies by descent of populations indicated that the odds of developing lung cancer was significantly augmented in African-Americans for both polymorphisms, and was non-significant or remarkably lowered in East Asians for CHRNA3 gene rs1051730 polymorphism (allelic model: OR = 1.51; 95% CI: 0.76–3.0; P = 0.237; and dominant model: OR = 1.22; 95% CI: 0.59–2,52; P = 0.592) (Table 2), and AGPHD1 gene rs8034191 polymorphism (allelic model: OR = 1.03; 95% CI: 0.47–2.27; P = 0.934; and dominant model: OR = 0.72; 95% CI: 0.52–0.99; P = 0.043) (Table 3).