TLR1 is a pattern recognition receptor that functions as a key component of innate immunity by recognizing bacterial lipopeptides. It forms heterodimeric complexes with TLR2 to detect diacylated and triacylated lipopeptides from microbial pathogens 1. Upon ligand engagement, TLR1:TLR2 complexes assemble into an activation cluster with CD14 at the cell surface, which then translocates to the Golgi apparatus via lipid-raft dependent mechanisms 2. This triggers MyD88 and TRAF6-dependent signaling cascades leading to NF-κB activation, inflammatory cytokine production (including IL-6, IL-8, and TNF), and orchestrated innate immune responses 3. TLR1 is located on the plasma membrane where it senses extracellular pathogen-associated molecular patterns 4. Recent evidence demonstrates that TLR1 recognizes non-canonical lipid ligands, such as diacyl phosphatidylethanolamine from Akkermansia muciniphila, which can modulate immune tone at low concentrations 5. Clinically, TLR1 genetic polymorphisms have been associated with gastric cancer susceptibility; carriers of the TLR1 rs4833095 TC genotype demonstrated increased gastric cancer risk in European populations 6. Additionally, TLR1 shows potential causal involvement in breast cancer risk based on Mendelian randomization analyses 7, suggesting roles beyond infection defense.