After treatment of SKBR3 and ZR75 cells with chalcone compounds (DK-13 and -14) at the concentrations of 10 and 20 μM for 48 h, DK-13 was more effective than DK-14 in inhibiting the proliferation of HER2-positive breast cancer cell lines, especially in late the apoptotic phase (Figure 3) (Supplementary Figure S1). The gene discussed is ERBB2; the disease is breast cancer.