BAI1 was isolated from p53 target genes and observed to be expressed specifically in the brain tissue, although this expression was absent in the majority of human glioma cell lines and downregulated in metastatic brain tumors from primary lung adenocarcinoma, indicating that BAI1 may be a tumor suppressor gene for intracranial neoplasms (6,7). This evidence concerns the gene ADGRB1 and lung adenocarcinoma.