Analysis of members of the TLR4 signal transduction cascade revealed comparable expression levels of Myd88 and TRAF6 in MDA-MB-435-Hyg breast cancer cells and M13MDA435 hybrid cells, whereas in M13SV1-EGFP-Neo breast epithelial cells the expression levels of these proteins were much lower. This evidence concerns the gene TLR4 and breast carcinoma.