TNF and neoplasm: With respect to the impact of hypoxia-induced alternative splicing on apoptosis [158], in breast cancer cells, chronic hypoxia promotes alternative intron 1-retention splicing in the TNF family member TNFSF13, resulting in suppression of TNFSF13 anti-apoptotic activity, implicating hypoxia-induced TNFSF13 alternative splicing in tumour suppression [56].