DSPP and cancer: Dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), and osteopontin (OPN) are three members of the Small Integrin-Binding LIgand N-linked Glycoprotein (SIBLING) family of proteins [10] reported to be up-regulated in a number of cancers, including breast, lung, prostate, and OSCCs [11, 12].