The SPSS Statistics 17.0 package was employed to correlate clinical and biological variables by means of Fisher’s test or a non-parametric test when necessary. Experiments were performed in triplicate, and data were presented as mean ± SD. Student’s t test was used for statistical analysis, and data from more than two groups were analyzed by one-way ANOVA in SPSS Statistics 19.0 and a subsequent Fisher’s least significant difference t test. Results were considered significant when p < 0.05. Association tests on ZNF750 genotype and levels were performed on log-transformed expression values by linear regression or t test.