CD44 and neuroblastoma: In a previous work, we investigated the cytotoxicity and the perturbation on cytoskeleton actin of hyaluronan (HA)-functionalized spherical AuNP, about 10 nm in size, on CD44-positive prostate tumor cells in comparison with neuroblastoma cells, which do not express the CD-44 HA binding receptor; a receptor-dependent perturbation effect by HA-AuNP on cytoskeleton actin and lysosomal organelles was demonstrated [14].