In addition, infection studies and other functional analyses in Mongolian gerbils (Franco et al., 2008), transgenic mice (Ohnishi et al., 2008), Drosophila (Reid et al., 2012), zebrafish (Neal et al., 2013), as well as stem cells in humans and mice (Sigal et al., 2015) have demonstrated that cagA expression is required and sufficient to trigger cell proliferation and even malignancy. This evidence concerns the gene S100A8 and infection.