*Lung cancer*

Expression of IGFBP7 in lung cancer cell lines using RT-PCR revealed decreased expression of IGFBP7 compared to controls, and 42 out of 90 patients with primary lung tumors exhibited negative staining of IGFBP7 by immunohistochemical analysis [118]. There was a significant correlation between DNA methylation of exon/intron 1 region and IGFBP7 downregulation. When a p53 expression vector was transfected into lung cancer cell lines, it could only induce expression of IGFBP7 in the unmethylated cell line, but not in the methylated cell lines, suggesting that IGFBP7 might be regulated by p53 in lung cancer cell lines.
