Apart from TLR9, monophosphoryl lipid A (MPLA), a TLR4 ligand derived from the lipopolysaccharide (LPS) of Salmonella Minnesota, is used as an adjuvant in a prophylactic vaccine against human papillomavirus types 16 and 18, which are common causes of cervical cancer (109). Here, TLR4 is linked to cervical cancer.