NOD1 and Rickettsiosis: Although Rickettsia are aflagellated, it is reasonable to speculate that an inflammasome or Nod1/2 response would be elicited upon Rickettsia infection based on the following points: (1) the cytosolic location of the bacteria; (2) the presence of both peptidoglycan and LPS in the Rickettsia cell wall, which are known stimulants of Nod1/2 and the caspase-11/4/5-dependent inflammasome, respectively; and (3) large amounts of secreted IL-1β and IL-18 from infected macrophages (119; personal observation).