HNRNPA2B1 and breast carcinoma: Alizarin Red S staining assays showed that exosomes from hnRNPA2B1 KD breast cancer cells inhibited the formation of calcium nodules, an effect that was reversed by exosomes from hnRNPA2B1 KD breast cancer transfected with miR-6881-3p mimics (Fig. 6A & S3A, Fig. S4A, Fig. S5A).