Consistent with our observations, myeloma cell could secrete RANKL [29], and high [Ca2+]o increases secretion of RANKL through activation of calcineurin/NFAT signaling in osteoblasts [30], and previous studies showing that both N-terminal and C-terminal region of NFATc1/NFATc3 contain calcineurin binding site [31, 32]. This evidence concerns the gene NFATC1 and plasma cell myeloma.