As cancer progression markers, exosomes with specific integrins predict metastatic organotropism.59 Tumor-derived exosomes contain integrins that prepare organ-specific sites where metastatic niches are established.59 These exosomes are uptaken by targeted resident cells like fibroblasts, macrophages, epithelial, and endothelial cells where they activate Src signaling and pro-inflammatory S100 gene expression.59 In murine breast cancer models, specific integrins, transferred by exosomes, determine the target organs where metastatic niches are prepared. This evidence concerns the gene SRC and breast cancer.