Interestingly, high TSP1 expression in MCF7 cells promoted the transendothelial migration significantly (Supplementary Figure S6), indicating that breast cancer cells gain the metastatic capability by high TSP1 expression, and TSP1-enriched exosomes further promote the cancer cell transendothelial migration of cancer cells by disrupting the integrity of HUVECs. The gene discussed is THBS1; the disease is cancer.