Studies have reported that lower CLDN23 mRNA levels are associated with poorer OS.[40,57] There is also a Cox multivariate survival analysis showing that when CLDN23 is low expressed, the OS of gastric cancer patients is longer.[58] A recent study showed that low expression of CLDN23 was associated with longer OS in colorectal cancer patients of CMS4 and C4 subtypes. Here, CLDN23 is linked to colorectal cancer.