CXCL8 and infection: Upon infection of AGS cells with the cagA-negative isogenic strain, which did not produce CagA and thus failed to deliver CagA and subsequent induction of the hummingbird phenotype, IL-8 mRNA was induced to the level that was comparable to those induced by infection with wild-type Hp_TH2099 or the G27 standard H. pylori strain (Supplementary Fig. S9c).