In a study by Krupa et al., which used a more sophisticated “two-hit” model (LPS priming followed by administration of an immune complex), Btk siRNA was conjugated with fragments of F(ab′)2 of an antineutrophil antibody (Ly-6G1A8) and administered intranasally after initial LPS exposure but prior to final reproduction of ARDS. Here, BTK is linked to acute respiratory distress syndrome.