In the first group, 17 patients with lung cancer and stable angina pectoris (of whom eight had been treated for more than 3 months with transdermal NTG patches delivering 25 mg/day), had their resected tumours immunohistochemically analysed to investigate the long-term effects of NTG treatment on HIF-1α, P-gp, VEGF, p53, and activated p53 (phosphorylated p53 at serine 15). This evidence concerns the gene HIF1A and neoplasm.