An exploratory study investigating novel markers predicting pathological response to chemoradiotherapy for rectal cancer using a 2D-DIGE (difference gel electrophoresis) quantitative proteomic approach in 35 patients with rectal cancer found higher Prx4 expression in pre-treatment tumor samples in poor responders to chemoradiotherapy, suggesting a potential role as a predictive biomarker of response to chemoradiotherapy for rectal cancer [56]. This evidence concerns the gene PRDX4 and neoplasm.