Similarly, the ABCG2-overexpressing S1-MI-80 human colon cancer cells, MCF7-FLV1000 human breast cancer cells, and H460-MX20 lung cancer cells were significantly resistant to HS-173 as compared to the parental S1 (Figure 1C), MCF7 (Figure 1D), and H460 cells, with calculated RF values of 10, 12, and 5, respectively. This evidence concerns the gene ABCG2 and malignant colon neoplasm.