Also, the expression levels of ANXA6 in PR-BC cells were much higher than that of PS-BC cells (Supplementary Figures 2C–E), and PR-BC-exo delivered ANXA6 protein for its upregulation in PS-BC cells (Supplementary Figures 2F–H), which encouraged us to select exosomal ANXA6 for further investigation. Here, ANXA6 is linked to breast cancer.