Our team has demonstrated that soluble TNFα (sTNFα) secretion by HER2+ breast cancer cells induces resistance to the anti-HER2 therapy trastuzumab, by upregulating the expression of the transmembrane glycoprotein mucin 4 (MUC4) through activation of the NF-kB pathway (31, 115). Here, ERBB2 is linked to breast carcinoma.