The detailed procedure was reported previously [24 (link)]. MCF10DCIS cells isolated from mammospheres were stained with antibodies against CD44-APC, Clone G44–26 from BD Biosciences (Cat# 559942, RRID: AB_398683) and CD10-PE from Thermo Fisher Scientific (Cat# 12–0106-41, RRID: AB_10714985). The stained MCF10DCIS cells were analyzed by flow cytometry using an FC500 Analyzer (Beckman Coulter) to determine the percentage of 4 different CD44/CD10+, CD44+/CD10+, CD44/CD10 and CD44+/CD10subpopulations.