CXCL8 and central nervous system cancer: Glioma patients had a significantly higher frequency of IL-8 -251 AA genotype (OR =1.91, 95 % CI = 1.22, 3.00; P = 0.005) and IL-8 -251 A allele (OR =1.36, 95 % CI = 1.08, 1.70; P = 0.009) than controls (Table 3).