PTBP1 and neoplasm: Furthermore, PTBP1 binds the 5′ UTR internal ribosome entry site in HIF1α mRNA, enhancing HIF1α translation, and accounts for 40–50% of hypoxia-stabilized HIF1α levels [122], increasing the influence of hypoxia-induced LUCAT1/PTBP1 complexing on tumour suppressor inactivation through alternative splicing [123] (Fig. 2b).