CD44 and neoplasm: Next, we examined the expression of epithelial-to-mesenchymal transition (EMT) markers as well as molecular effectors of the tumor microenvironment, such as CD44, the main hyaluronan receptor that also acts as a co-receptor for MIF, the hyaluronan oncogenic network, and specific matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs).