As a lipopeptide derived from mycoplasma and a potential agonist of TLR2/6 heterodimers in DCs (Takeda et al., 2018), MALP-2 is the most widely studied TLR2 adjuvant and has attracted great interest as a novel and efficient built-in adjuvant for vaccines against infectious diseases (McDonald et al., 2014; Muhlradt et al., 1997). Here, TLR2 is linked to infectious disease.