TGFB1 and cancer: Moreover, HIF1α signalling has been shown to induce telomerase activity through human telomerase reverse transcriptase (hTERT) expression, which in turn leads to cellular transformation.82 In addition to this, the HIF1 complex initiates transcription of metabolic genes, survival and growth factors (such as PDGFB, transforming growth factor β [TGFβ], insulin-like growth factor-II [IGF-II]) and angiogenesis factors, including vascular endothelial growth factor [VEGF] (reviewed in ref. 83) to initiate cancer.