SPP1 and neoplasm: Secreted Phosphoprotein 1 (SPP1) gene encodes for Osteopontin (OPN), a sialic acid rich, chemokine-like, matricellular phosphoglycoprotein, with well-defined roles in cell-matrix interaction, inflammatory responses, angiogenesis, and tumor metastasis (Shevde and Samant, 2014).