In addition, we suggest that the differential DNA methylation of the TLR4 promoter in gastric cancer cell lines expressing TLR4 at high and low levels is an important mechanism underlying TLR4 transcription, with TLR4-silenced cells showing increased MeCP2 binding and TLR4-upregulated cells showing enhanced Sp1 binding, to the TLR4 promoter. Here, SP1 is linked to gastric cancer.