Also, pro-ApoA-I levels were found upregulated in the serum of lung cancer patients with brain metastases and overexpressed at transcriptional level in metastases of colon adenocarcinoma to the liver suggesting that, in these particular situations, ApoA-I levels could be used as a biomarker for the extension of the disease to the brain and the liver, respectively [87,96,148]. The gene discussed is APOA1; the disease is lung cancer.