FASLG and cancer: For the FasL -844C>T polymorphism, genotyping method (χ2 = 9.21, degree of freedom = 3, Ph = 0.027), but not cancer type (χ2 = 4.33, degree of freedom = 7, Ph = 0.741), ethnicity (χ2 = 5.64, degree of freedom  = 3, Ph = 0.131), or source of controls (χ2 = 0.08, degree of freedom  = 1, Ph = 0.777) contributed to substantial heterogeneity.