The present study demonstrated that CLDN18 positivity in PD-positive gastric cancers was 54.8% at 40% cut-off and 28.6% at 75% cut-off in primary tumors, and the frequency was slightly lower in disseminated lesions, showing positivity in 44% at 40% cut-off and 20.2% at 75% cut-off. Here, CLDN18 is linked to gastric cancer.