TLR2 and neurodegenerative disease: Several of them, especially TLR2, 4, and 9, have vital contributions to the development of neurodegenerative diseases.276 TLRs can be activated by pathogen-associated molecular patterns (PAMPs) (e.g., bacteria, viruses, or fungi) and DAMPs (e.g., protein aggregates, ATP, mtDNA).277 TLR activation leads to receptor dimerization and the recruitment of adapter proteins, such as Toll/interleukin 1 receptor (TIR) domain-containing adapter interferon-β (TRIF) and myeloid differentiation primary-response protein 88 (MyD88)276 (Fig. 6).