To determine whether the protection induced by d7EB cells could be ascribed to secreted factors, cultured d7EB cells were stimulated overnight with LPS, 1 g/ml, or medium alone. Addition of LPS-conditioned medium obtained from d7EB cells did not alter mortality in mice that underwent CLP compared with controls injected with nonconditioned medium or PBS ( Figure 3C ), indicating that d7EB cells were essential for protection.