In our previous study, we improved the extraction method and adopted the systematic solvent method to extract Huaier into five organic phases: petroleum ether, ethyl acetate, n-butanol, ethanol, and water, and identified the n-butanol extract of Huaier (named as NEH) as the most effective components against GC in vitro. Additionally, we confirmed that NEH was more effective in inhibiting GC cells compared with the aqueous extract of Huaier and was able to significantly enhance the effect of cisplatin in GC cells by reducing the expression of MRP1 (multidrug resistance-associated protein 1). The gene discussed is ABCC1; the disease is gastric cancer.