S100A8 and infection: Next, a co-culture model of human GC cell lines HGC-27 or AGS and H. pylori (100:1) was established (Figure S1F), and the changes of intracellular cholesterol before and after infection with H. pylori were measured by ELISA, which demonstrated that only CagA-positive H. pylori could cause significant upregulation of intracellular cholesterol in GC cells (Figure 1E).