Niban has been cloned from cell lines derived from Eker rat by AFLP-Differential Display method as a novel gene which is increased in the early stage of renal carcinogenesis (ref. 6). Then, it has been reported that Niban protein is expressed in various cancer tissues including thyroid cancer. In research of recent years, it has been reported that Niban is an ER stress-inducible protein and it regulates phosphorylation of eIF2α and S6K1/4E-BP1 (ref. 3).