VIM and breast cancer: After detecting the expression levels of keratin and vimentin in breast cell lines and patients with breast cancer, Polioudaki H and colleges introduced a novel parameter, the vimentin/keratin ratio (Vim/K ratio), to reflect the EMT status of CTCs: a low Vim/K ratio suggested an epithelial phenotype, whereas a high Vim/K ratio indicated a mesenchymal phenotype in CTCs.