GDNF and carcinoma: Within a complex and diverse range of cell types in OS tissues, including osteoblastic OS cells, carcinoma associated fibroblasts (CAFs), B cells, myeloid cells 1, myeloid cells 2, NK/T cells, plasmocytes, ARTN and NRTN genes had the highest expression in Osteoblastic OS cells, GDNF gene had a peak expression in carcinoma associated fibroblasts, and PSPN gene in endothelial cells.