Considering the fact that As3+ is a human carcinogen and As3+ induces ATF6 and ATF6B, we next evaluated expression of ATF6 proteins in human lung adenocarcinoma tissues that were case-matched with the adjacent normal lung tissues using human tissue microarray (TMA) panels (LC10013c, US Biomax Inc. Rockville, MD, USA). Here, ATF6B is linked to lung adenocarcinoma.