Our results show that 1) AUR had the ability to induce the activation of ERK1/2 in not only cortical neurons but also the rat pheochromocytoma cell line (PC12 cells), which is a model system for studies on neuronal proliferation and differentiation; and 2) AUR had the ability to promote neurite outgrowth from PC12 cells. Here, MAPK3 is linked to pheochromocytoma.