Coexpression of CK, Twist and vimentin in the same cell. Representative confocal laser-scanning photomicrographs of CTC cytospin after negative immunomagnetic separation in a patient with metastatic breast cancer. Cells were triple-stained with pan-CK A45-B/B3 antibody/Zenon Alexa Fluor 488 (green)/Twist anti-mouse/Alexa Fluor 633 anti-mouse antibody/vimentin anti-rabbit/Alexa Fluor 555 anti-rabbit antibody (orange). Original magnification, x600. (A) A CTC expressing CK, Twist and vimentin. (B) A CTC expressing CK and Twist, but not vimentin. CK = cytokeratin; CTCs = circulating tumour cells.