Censini et. al. 7 designated a segment of DNA from cagA + strains which is present in PAI as cag II, and the segment that contains the cagA gene as cag I. However a study by Akopyants NS, et. al.
Censini y col 7 designaron como cag II a un segmento de DNA de cepas cagA+ presente en PAI y cag I al segmento que contiene el gen cagA.