CLDN18 and neoplasm: Thus, we finally examined the association between CLDN18.2 expression in GC tumor tissues and the frequency of peripheral blood NK cells, including CD56dimCD16+ and CD56brightCD16− NK cells, as well as monocytes, including classical (CD14++CD16–), intermediate (CD14++CD16+), and non-classical monocytes (CD14+CD16++) (Supplementary Fig. S3).