In the mice injected with the GNP–antigen–CFA complex, tumor induction could have been due to an inflammatory process in the tumor microenvironment that could have been caused by immunization with CFA and by increased contents of IL-1β, IL-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1), observed in breast cancer patients [49,50]. Here, IL6 is linked to breast cancer.