non-coding RNAs play important roles in the regulatory network of Claudin-4. As such, non-coding RNAs should be considered as potential biomarkers and therapeutic targets against gastric cancer. During the complex process of metastasis, primary cancer cells undergo a sequential series of events including local dissemination, intravasation into the vascular system, survival in the circulatory system, extravasation out of the vascular system,and regrowth at distant sites3,4,5.Among these ncRNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have appealed to a large group of researchers and become a main focus of attention.Kaplanâ??Meier analysis of the correlation between CLDN4 expression levels and overall survival.