CD44 and cancer: Spheroids were firstly characterized from a morphometric point of view, including dimension and aspect ratio parameters; then, qPCR analyses of cancer stem cell-related genes (i.e. CD44), mesenchymal gene (i.e. VIMENTIN), cytokine gene (i.e. TGF-β1) and proliferation gene (i.e. Ki-67) were carried out on cells constituting spheroids in order to characterize them from a molecular point of view.