MKP-1 knockdown decreased viable cell number. rIEC-6 cells were transfected with scramble siRNA (scramble) or siRNA against MKP-1 (siMKP-1) and allowed to proliferate for 24 h. Plates were seeded with 4 × 105 cells per well. Cells were then stimulated with high-dose LPS (100 μg/ml) for 48 h. Trypan blue exclusion was used to count viable cells. Data are shown as viable cell number as a percent change from cells seeded, with zero being no change in cell number after 48 h of growth. *siMKP-1, non–LPS-treated cells are different from scramble, non-LPS-treated, P < 0.05. **siMKP-1, LPS-treated cells are different from scramble, LPS-treated cells, P < 0.0001. All data shown from three independent experiments done in triplicate.