Breast cancer stem cell culture. Fluorescence light micrograph of an organoid stem cell culture of mammary (breast) tissue. Organoids are miniature versions of organs grown in the laboratory to allow testing of targeted therapies. This technique also helps identify networks of genes that control cellular behaviours and lead to cancers. This organoid was grown from a single mammary stem cell. it was used to demonstrate the criticality of the Sox10 gene (blue). This gene allows cells to migrate and to take on characteristics of other cells (plasticity). In cancer cells, these features lead to metastasis and drug resistance. The other colours show inner keratin-8+ luminal cells (green) and peripheral keratin-14+ basal cells (red).