CD44 and melanoma: Cells overexpressing CD44 have several cancer stem cell features, such as epithelial-mesenchymal transition capability, self-renewal, and resistance to radiotherapy and chemotherapy.49 Consistent with our results, a recent study by Yang et al on the synergistic effect of sorafenib and cisplatin in human osteosarcoma cells showed that cisplatin could significantly suppress cell proliferation, colony formation, migration, and invasion.50 In another study, the combination of Liquiritigenin and cisplatin was investigated in the invasion and metastasis of melanoma cells.