TLR2 and neoplasm: Results indicated that tumor-derived exosomes were transferred into the THP-1 human monocytic cells and significantly induced the production and secretion of various pro-inflammatory cytokines including interleukin (IL)-6, IL-1β, and IL-8, and tumor necrosis factor (TNF)-α, via TLR2 and TLR4 binding on the cell surface of monocytes, which subsequently activated nuclear factor κB (NFκB) and signal transducer and activator of transcription 3 (STAT3) (69).