Intensities varied statistically significantly as a function of NEP knockdown and DEP exposure. Labeled cRNA from mock or NEP siRNA-transfected cells was tested using two different Affymetrix U133 Plus human genome GeneChips, following 0, 10, 40 µg/cm2 DEP incubation. About 2158 probe sets, out of a total of 54,675, were detected above background and shown to be statistically different (P < 0.01) in the NEP siRNA experimental group when compared with mock controls.