TLR4 and infectious disease: At present, some TLR2 and TLR4 agonists have been used in peptide-based vaccines against infectious diseases, including TB, such as TLR2 agonists ESAT6 (144), phenol-soluble modulin α4 (PSMα4) (145), dipalmitoyl-S-glyceryl cysteine (Pam2Cys) (115, 146), and PorB (147, 148), TLR4 agonists RpfE (Rv2450c) (149), 50S ribosomal protein L7/L12 (RplL) (22, 150–155), heparin binding hemagglutinin (HBHA) (156), cholera toxin subunit B (CTB) (157–159), and RS-09 (160, 161).