To develop this compound to be a targeted drug for breast cancer, specific target identification was necessary for three reasons: (1) breast cancer comprises many receptors that relate to cancer treatment, (2) (−)-kusunokinin did not show strong binding with CSF1R and AKR1B1, and (3) synthetic (±)-kusunokinin contained two forms. The gene discussed is AKR1B1; the disease is breast carcinoma.