POLH and cancer: In addition to its well-established role in platin drug resistance, preclinical studies indicate that POLH-deficient cells are 3-fold more sensitive to the nucleoside analogs β-D-arabinofuranosylcytosine and gemcitabine, and even more sensitive (10-fold) to gemcitabine/cisplatin combination treatment (21), a commonly used clinical regimen for treating a wide spectrum of cancers, including bladder, pancreatic, ovarian, cervical, and non-small cell lung.