Tumor cells were identified by positivity for the common mesenchymal marker, Vimentin.151 While Vimentin positivity on OS and other tumors of mesenchymal origin is well known,152 this biomarker is also present on the surface of other mesenchymal components of the TME.153 Therefore, it is likely that various non-cancerous mesenchymal stromal cells, also positive for Vimentin, were included within our Tumor cell cluster. This evidence concerns the gene VIM and neoplasm.