CASP1 and escherichia coli infection: We also measured lactate dehydrogenase (LDH) and high mobility group protein 1 (HMGB-1) levels in the BALF, both of which are released during lytic cell death, and observed significantly higher levels of LDH and HMGB-1 in the BALF of the Casp1+/+ mice after E. coli infection (Figs 2C and S2G).