The elevated levels of αSMA-positive fibroblasts and blood vessels in the D2A1-m2 primary tumours in both the BALB/c immunocompetent (Fig. 6A; Fig. S1D,E) and NSG immunocompromised (Fig. 6B) mice suggest that this subline has an enhanced ability to promote stromal cell recruitment activation and this could, in part, provide a mechanistic explanation for the enhanced spontaneous dissemination of tumour cells to secondary sites. This evidence concerns the gene ACTA1 and neoplasm.