XPC and urinary bladder carcinoma: Substantial heterogeneities were observed in the overall analysis evaluating the association between XPC Lys939Gln polymorphism and bladder cancer risk in homozygous model (P = 0.000), heterozygous model (Gln/Gln vs Gln/Lys: P = 0.007), and allele comparison (P = 0.007), except for the heterozygous (Gln/Lys vs Lys/Lys: P = 0.348), dominant model (P = 0.397), and recessive model (P = 0.18).