Y138E has impaired transcriptional activity. C33A cells were transfected with WT (10 and 100 ng), Y138F (10, 100, and 200 ng), or Y138E (10, 100, and 400 ng) and the pGL2-E2BS-Luc reporter plasmid. After 48 h, cells were lysed and firefly luciferase levels measured using Dual-Glo luciferase reagent. Values are expressed as means ± SEM (n = 8). *, P ≤ 0.01 by two-tailed t test when compared to the no-E2 group. #, P ≤ 0.01 by two-tailed t test compared to E2 WT.