At 20 days, tumour spheroids from TrkAIII transfectants exhibited a significant 15.8±9.9 fold (t-test, p = 0.001, df = 4) larger mean volume than pcDNA transfectants and a significant 16.9±9.8 fold (t-test, p = 0.001, df = 4) larger mean volume than TrkA transfectants. Here, NTRK1 is linked to neoplasm.