Choi et al. [52] fermented Aronia melanocarpa juice with Lactobacillus rhamnosus and produced catechins that inhibited the growth of MCF7 and MDA-MB-231 breast cancer cells, thereby reducing the expression of Nanog, Sox2, and OCT4 genes in breast cancer stem cells and inhibiting the proliferation of breast cancer cells. The gene discussed is POU5F1; the disease is breast cancer.