SLC22A1 and cystic fibrosis: In this study, when p53 and OCT1 expression data were combined, either p53MT-ex or OCT1Low was a significant predictor of poor response in univariate and multivariate analyses of the entire cohort (univariate, P < 0.001; multivariate, P < 0.001), with higher levels of statistical significance compared with p53 alone, and in the univariate analysis of the CF group (P = 0.011) and the DCF group (P = 0.021).