TLR9 and pneumonia: Leveraging these defensive mechanisms, we identified a pneumonia-protective, synthetic PAMP-based therapeutic comprising a diacylated lipopeptide ligand for TLR2/6 (Pam2CSK4 [Pam2]) and a class C unmethylated cytosine-guanine (CpG) oligodeoxynucleotide ligand for TLR9 (ODN M362 [ODN].