For example, increased expression has been observed for voltage-gated Na+ channels [11]; voltage-gated Ca2+ channels were found to be involved in the pro-proliferative action of mitogen on a human lung adenocarcinoma cell line [12]; two-P K+ channels, one of which was KCNK9, were found to be over-expressed in more than 35% of lung tumors [13], and the over-expression of KCNK9 in cell lines promoted tumor formation and conferred resistance to hypoxia and serum deprivation [14]. Here, KCNK9 is linked to lung adenocarcinoma.