MAP2K3 and cancer: The mechanism of these anti‐cancer and anti‐angiogenic activities of PBSA involves inactivation of MKK3/6‐p38MAPK‐dependent signalling pathways and subsequent down‐regulation of MMP‐9, MMP‐2, Cdk4, Cdk2, integrin β1 and VEGF expression, which are closely associated with cancer cell growth and progression as well as angiogenesis.