Mbaveng et al. [33] conducted research on sauyauxnium chloride, an indoloquinazoline alkaloid derived from the medicinal herb Araliopsis soyauxii Engl, and found that it had IC50 values below or around 10 μg/mL with regard to 14/18 (77.8%) cancer cell lines, including two drug-resistant breast cancer cells (MDA-MB-231-pcDNA and MDA-MB-231-BCRP). This evidence concerns the gene ABCG2 and cancer.