BioC and BC upregulated the mRNA expression of Opn (Fig. 1a), a typical osteoblastic marker,23 which was also induced by CaCl2 (10 and 20 mM, Fig. 3a), suggesting that Ca2+ released from BioC and BC are involved in the upregulation of Opn mRNA expression. This evidence concerns the gene SPP1 and breast cancer.