TLR4 and cancer: MSNs combined with anti-PD-1 for cancer therapy, promote cytotoxic T lymphocyte infiltration through TLR4-NFκB axis and lead to in vitro and in vivo Ccl5/Cxcl9/Cxcl10 production to overcome anti-PD-1 resistance, to establish a T-cell inflammatory microenvironment [171].