HSPA5 and acute respiratory distress syndrome: In order to ascertain the role of BiP both in primary endothelial cells and in a LPS inhalation murine model of ALI, we used Subtilase cytotoxin (SubAB), the prototype of a family of AB5 cytotoxins produced by Shiga toxigenic Escherichia coli, or its isolated catalytic A subunit (SubA), that specifically cleaves BiP/GRP78 between a dileucine motif (Leucine416/417), resulting in inactivation of BiP28,29.