Considering the close relationship between the suppression of the c-Met and HER2 and the cellular autophagy, the C-9′ hydroxyl group of araguspongine C was supposed to be the crucial pharmacophoric group for its notable anti-proliferative activities against breast cancer cell lines and in vitro enzyme inhibition activities, compared with another oxaquinolizidine alkaloid of araguspongine A without the C-9′ hydroxyl group. The gene discussed is ERBB2; the disease is breast cancer.