CASP4 and Doyne honeycomb retinal dystrophy: Caspase-4 noncanonical inflammasome is activated by intracellular LPS [1,2], thus, the elevated caspase-4 noncanonical inflammasome activity found in DHD patients may be an indication of a higher intracellular bacterial load in these patients Interestingly, serum endotoxin levels were not elevated [54], suggesting the need for further studies to clarify the relationship between serum endotoxin concentrations and caspase-4 noncanonical inflammasome activity in DHD.