EGFR and breast cancer: Importantly, by targeting EGFR+ tumor/PDGFRβ+ stromal cells in the entire tumor bulk, the dual-aptamer-engineered nanoparticles resulted more effective than unconjugated or single-aptamer-conjugated nanoparticles in either 3D spheroids cocultures of tumor cells and MSCs, and in breast cancer organoids derived from pathologically and molecularly well-characterized tumors.