TLR3 and neoplasm: PRRs, such as Toll‐like receptor (TLR) 2, TLR3 and TLR8, are activated by proteins (heat shock proteins 70 and 72), small nuclear RNA, and microRNAs (miRNA‐21 and miRNA‐29a) in tumour cell‐derived EVs, respectively; they mediate the function of the innate immune response to promote tumour metastasis (Chalmin et al., 2010; Fabbri et al., 2012; Liu et al., 2016, 2010).