CD44 and osteosarcoma: Based on these assumptions, in a subsequent work [16], hyaluronated liposomes containing the same H2S-DOXO (HALs-H2S-DOXO) were prepared with the aim of exploiting the overexpression in osteosarcomas of the hyaluronic acid (HA) receptor CD44, known to promote tumor growth and metastatic spread [17,18] and whose silencing improves the response to DOXO and other anticancer drugs [19].