TLR4 and neoplasm: Calreticulin binds to CD91 and stimulates DC to engulf tumor antigens [54]; (2) chemotherapy drugs induce the autophagy of tumor cells by activating TLR3 on the surface of cells, and adenosine triphosphate is released to recruit DC into tumor focus; and (3) high-mobility group protein B1 is released and combined with TLR4 to activate the signal pathway [55].