MAPK3 and cancer: Various alkaloids like vincristine, vinblastine, evodiamine, sanguinarine, matrine, tetrandrine, camptothecin, and berberine have already proved their anti-cancer potentials via targeting different kinds of essential signaling molecules such as MAPK, extracellular signal-related kinases 1/2 (ERK1/2), tumor suppressor protein (p53), p38 mitogen-activated protein kinase, c-Jun N-terminal kinase (JNK), and PI3K/Akt.