PPARD and central nervous system cancer: Rs2016520 and rs1053049 of PPARD had a decreased glioma risk in allele (rs2016520: OR = 0.82, 95%CI = 0.68–0.99, P = 0.041; rs1053049: OR = 0.78, 95%CI = 0.64–0.95, P = 0.012), dominant (rs2016520: OR = 0.78, 95%CI = 0.62–1.00, P = 0.047; rs1053049: OR = 0.75, 95%CI = 0.59–0.96, P = 0.020) and additive (rs2016520: OR = 0.81, 95%CI = 0.67–0.99, P = 0.037; rs1053049: OR = 0.78, 95%CI = 0.64–0.95, P = 0.012) models.