CD44 and breast cancer: The combination of docetaxel- and sulforaphane-loaded PLGA-hyaluronic acid based NPs (DTX-SFN-PLGA-HA NPs) inhibited breast CSCs through decreased expression of cyclin D1 and β-catenin in MCF-7 breast cancer cells but was less effective in MCF-7 mammospheres with an epithelial-specific antigen (ESA)+CD44+CD24− phenotype.