SPO11 and Infertility: In a subgroup analysis by ethnicity, we observed a significant association between SPO11 C631T polymorphism and male infertility risks in Chinese (TT + CT vs. CC: OR = 5.02, 95%CI = 2.79–9.06; CT vs. CC: OR = 5.02, 95%CI = 2.79–9.06; T vs. C: OR = 4.75, 95%CI = 2.66–8.48), whereas there was no significantly elevated infertility risks associated with the SPO11 C631T polymorphism and male infertility in Iranian population (TT + CT vs. CC: OR = 2.55, 95%CI = 0.82–7.92; CT vs. CC: OR = 2.44, 95%CI = 0.76–7.84; T vs. C: OR = 2.56, 95%CI = 0.87–7.52).