TLR7(Toll-like receptor 7) is a member of the Toll-like receptor (TLR) family which plays a fundamental role in pathogen recognition and activation of innate immunity. TLR7 is often associated with viral infections. Upon activation, TLR7 initiates a signaling cascade that leads to the production of pro-inflammatory cytokines and type I interferons, essential for mounting an effective immune response. This function is particularly important in the context of viral infections, as TLR7 helps the body detect and respond to pathogens early in the infection process. TLR7 is predominantly expressed in immune-related tissues such as the lung, placenta, and spleen, where TLR7 contributes to the regulation of immune responses.