TLR1 and Lyme disease: We have previously demonstrated that a single-nucleotide polymorphism (SNP; 1805GG) in the host toll-like receptor 1 (TLR1), a key pathogen sensing receptor for borrelia, is associated with more symptomatic early Lyme borreliosis and a greater frequency of postantibiotic, chronic inflammatory Lyme arthritis (12,14).