One study on gemcitabine-resistant variants of human intrahepatic CCA cell lines, KKU-M139 and KKU-M214, showed significantly lower expression levels of hENT1 mRNA in the gemcitabine-resistant cells compared to their parental cells (Wattanawongdon et al., 2015). The gene discussed is SLC29A1; the disease is cholangiocarcinoma.