TLR4 and cancer: Finally, to further compare whether the expression of the TLR4 gene is different in the cancer tissues of 14 types of tumors and the corresponding normal tissues, both the HPA database and IHC staining were verified, and the results confirmed that the TLR4 gene was significantly highly expressed in COAD, LIHC, OV, PRAD, BRCA, PAAD, and UCEC (Figures 7, 8 and Table 3).