VIM and neoplasm: Primary tumours generated from 2D and 3D TGFβ cells exhibited a larger vimentin‐positive number of cells, which were also more elongated and often arranged in parallel streaks, suggesting that EMT was evident within the primary tumour when the xenotransplanted cells were pre‐treated with TGFβ prior to injection in the mammary fat pads (Fig. S9B).