- The human DNA polymerase lambda interacts with PCNA through a domain important for DNA primer binding and the interaction is inhibited by p21/WAF1/CIP1. Maga, G., Blanca, G., Shevelev, I., Frouin, I., Ramadan, K., Spadari, S., Villani, G., Hübscher, U. FASEB J. (2004)