SPP1 and cancer: It is located on the long arm of chromosome 4 region 13 (4q13) [12] and is found in different forms in the body i.e. full length osteopontin (OPN-FL), OPN-R elicited in various immune responses [13], [14], OPN-L with unknown function, intracellular OPN involved in migration, fusion and motility [15]–[18] and osteopontin-a, osteopontin-b and osteopontin-c, the cancer specific splice variants [19], [20].