VIM and neoplasm: Immunohistochemistry of primary tumours confirmed that 2D control cells gave rise to tumours that contained a fair proportion of RFP‐positive cells intermixed with RFP‐negative cells, whereas all other conditions showed low or very low RFP content, correlating directly with tumour cell E‐cadherin expression and inversely with mesenchymal cell protein vimentin expression (Fig. S9A,B).