NER is not required for expression of AREG and EREG. Using lentiviral transfection stable knockdown of XPA (A), ERCC4 (XPF) (D), and ERCC5 (XPG) (G) was achieved in Panc1-2G6 (low α6β4) and Panc1-3D7 (high α6β4) cells as confirmed by QPCR. AREG and EREG expression was examined following knockdown in cells with both low α6β4 (B,E,H) and high α6β4 (C,F,I) expression. Data depicted are representative of at least three different experiments and represent the mean +/− standard deviation. Statistical significance was calculated using a one-tailed t-test in which * denotes P < 0.05 as compared to controls.