Malignant tumors showed a higher frequency of PSMA expression (score 2) as compared to benign tumors, with a high frequency in rhabdomyosarcoma (2 of 2, 100%), mesenchymal chondrosarcoma (14 of 20, 70%), undifferentiated sarcoma of bone (4 of 6, 67%) and of soft tissue (13 of 20, 65%), and osteosarcoma (46 of 81, 57%). This evidence concerns the gene FOLH1 and osteosarcoma.