SPP1 and bone neoplasm: Among a cohort of 29 healthy individuals, the serum osteopontin levels ranged from 10.06 to 13.35 ng/ml [11]. Within a group of 153 patients diagnosed with bone tumors, 72 individuals with benign bone tumors exhibited serum osteopontin levels ranging from 46.68 to 65.68 ng/ml, while 27 osteosarcoma patients demonstrated higher serum osteopontin levels, ranging from 218.92 to 308.41 ng/ml [11].