Cancer cells are known to undergo extensive metabolic reprogramming, which allows them to adapt to the hypoxic and nutrient-poor conditions of their microenvironment. However, how these changes contribute to tumorigenesis is not clear. Suppression of OXPHOS in bratRNA-expressing flies inhibited tumour growth and rescued bratRNAiinduced fly lethality. Moreover, exposition of bratRNA-expressing flies to low oxygen reduced tumour growth. Importantly, these manipulations did not impact proliferation of normal NBs, indicating that oxidative metabolism is a hallmark of tNBs and is required for their proliferation.