... interaction of both proteinsor by binding of CagAPYto Csk, a negative regulator of Src [6,7]. Because Src is the primary kinase phos-phorylating CagA in the EPIYA-motifs, inhibition of Src by ... the disrup-tion of cell–cell junctions, a loss of cell polarity andthe induction of pro-inflammatory and mitogenicresponses (Fig. 3C). The first detected interaction part-ner of nonphosphorylated ... represents one of the most successful humanpathogens, inducing severe clinical symptoms only ina small subset of individuals, mirroring a highlybalanced degree of co-evolution of H. pylori andhumans....