RRM1 and adrenal cortex carcinoma: Henning et al., investigated in ACC patients receiving Gem-based chemotherapy the prognostic and predictive role of the tissue expression of the human equilibrative nucleoside transporter type 1 (hENT1) and the subunit M1 of ribonucleotide reductase (RRM1), two enzymatic activities involved in response or resistance to Gemcitabine.