CD44 and neoplasm: The nanogel avoided drug resistance via the following pathways, 1) the intracellular environment of tumor cells enriched with NGs due to specific internalization via CD44-mediated endocytosis leads to reduced P-gp efflux of NGs, 2) combination of DOX and cisplatin tackled clinical MDR, and 3) drugs were released at tumor pH because of disintegration of the compacted structure at acidic pH.