A1 and A20 inhibit LPS-initiated endothelial apoptosis. (A) HMEC-1 cells stably transduced with various cDNA constructs, as indicated, were exposed to LPS and CHX (50 μg/mL). MTT assays were performed at 15 hours after treatment with LPS and CHX. Each data point is the proportion of viable cells with respect to cells treated with medium only (Med). Results are the means + SD of three experiments. (B) Each of the transduced cell lines was tested for expression of the relevant protein by immunoblotting.