D. Bhattacharya and N. Yusuf discuss the data regarding TLR expression in breast cancer and its role in inflammation and cell survival in the tumor microenvironment in “Expression of Toll-like receptors on breast tumors: taking a Toll on tumor microenvironment.” The immune system is intricately involved in the process of tumor progression and metastasis and can play key roles in both tumor promotion and tumor suppression. Here, TLR4 is linked to neoplasm.