TLR4 and neoplasm: The activation of TLR2/TLR4 by HSPs causes the activation of HSF1 signaling followed by NF-kB signaling in DCs, resulting in the release of cytokines (IL-1, IL-6, and TNF) and the release of tumor antigens, which can be processed by APCs (Figure 4a) [17,18,19,23,28,29,38,39,45,53].