Altered expression of Cldn7 is observed in various cancer types (Kominsky et al., 2003; Ouban and Ahmed, 2010; Dahiya et al., 2011; Lu et al., 2011; Tsujiwaki et al., 2015; Ono et al., 2016), yet the exact role of Cldn7 in cancer progression is still unclear. The gene discussed is CLDN7; the disease is cancer.