A functional experimental study showed that KLF4 overexpression significantly promoted apoptosis and inhibited cell cycle progression in vitro, and reduced the tumorigenicity of GC in vivo.31, 32 Besides, KLF4 inhibits cell proliferation, promotes cell differentiation and is closely related to tumor development.21, 22 Targeting KLF4 in advanced solid tumors has been approved for clinical trials.7 In this study, we show that KLF4 expression is lower in both GC patient’ samples and cell lines compare to controls. The gene discussed is KLF4; the disease is neoplasm.