TP53 and lung cancer: To detail the effect of p53 on expression of BORIS isoforms, we induced ectopic p53 transcription in the H1299 lung cancer cell line, which is homozygous for deletion of p53. While BORIS subfamilies were expressed at very high levels in parental H1299 cells, the induction of p53 for 48 hours resulted in strong suppression of all subfamilies, except sf5 (Fig. 9E).