Interestingly, DUSP4 alone can still limit the ERK1/2 over activation leading to cancer stem cell formation and epithelial mesenchymal transition (EMT) instead of cell-cycle arrest.50 The inhibition of DUSP4 could prevent the EMT in breast cancer,50 as well as causing cell cycle arrest, similarly as the inhibition of DUSP3 in colorectal cancer.46 Therefore, DUSP4 inhibitors (such as the CHEMBL 2146956 compound, which inhibits DUSP4 with an IC50 of 2.29 μm) are under intensive experimental investigations. The gene discussed is MAPK3; the disease is breast cancer.