On the contrary, only a few studies have provided no evidence supporting the use of hENT1 as a predictive biomarker for gemcitabine efficacy in a neoadjuvant gemcitabine-based chemoradiation setting (Kawada et al., 2012) and in patients with advanced pancreatic cancer (Ormanns et al., 2014). This evidence concerns the gene SLC29A1 and familial pancreatic carcinoma.