HAS2 and neoplasm: The interaction between CD44 on the cell surface and HA in the ECM induces the activation of ZEB1, which, in addition to promoting EMT also inhibits epithelial splicing regulatory protein 1 (ESRP1) leading to the up-regulation of hyaluronic acid synthase 2 (HAS2) and increased HA production.113 Thus, the chemical composition and stiffening of the TME can promote (partial) EMT in tumour cells.