ARTN and neoplasm: GDNF is a neurotrophic factor traditionally known for its role in the development and maintenance of the nervous system.21,22 Recent research has expanded its relevance to oncology, particularly in OS.23 In the context of OS, GDNF has an emerging role in tumour growth, treatment resistance, and pain.13,22,24 Studies have shown that GDNF can influence OS cell proliferation, survival, and metastasis.