Confocal light micrograph of cultured cancer-associated fibroblast cells derived from a mouse breast cancer tumour. Fluorescent markers have been used to highlight structures. DNA (deoxyribonucleic acid) in cell nuclei is blue. Endosialin, a protein found on the surface of the cells, is red. Alpha tubulin, a component of microtubules is green. Microtubules are components of a cell's cytoskeleton. The cytoskeleton maintains the cell's shape, allows some cellular mobility and is involved in intracellular transport and nuclear division.