HP and infection: Hp infection was classified into four groups based on Hp infection status, CagA expression, and CagA subtypes: negative for infection [Hp(−)/CagA(−)/EPIYA‐C(−)/EPIYA‐D(−)]; CagA(−) infection [Hp(+)/CagA(−)/EPIYA‐C(−)/EPIYA‐D(−)]; Western‐type CagA(+) infection [Hp(+)/CagA(+)/EPIYA‐C(+)/EPIYA‐D(−)]; and East Asian‐type CagA(+) infection [Hp(+)/CagA(+)/EPIYA‐C(−)/EPIYA‐D(+)].