Cells expressing G908R NOD2 receptor are less responsive to ligand activation. Cells were treated with MDP (0.2-4 μg/ml) with endotoxin-free water as a control for 24 h. After 24 h, the media was collected and added to QUANTI-Blue™ solution for analysis of the SEAP. SEAP levels were measured via a spectrophotometer at 650 nm. Data shown = mean ± SEM, n = 4. ****p < 0.0001.