This work represents a comprehensive approach to study the histological changes and the effectiveness of clinical interventions to reduce gastric cancer risk in the Chilean population using a multiplex immunohistochemistry/immunofluorescence (mIHC/IF) technology and the simultaneous detection of TLR4, TLR5 and TLR9 on formalin-fixed and paraffin-embedded tissue sections of gastric epithelium obtained by endoscopic biopsy. The gene discussed is TLR4; the disease is gastric cancer.