For example, PGE2 signals through prostaglandin E receptor 2 (EP2) on neutrophils and tumor-associated fibroblasts, which promotes inflammation through multiple steps to form the tumor microenvironment in colorectal cancer (Aoki and Narumiya, 2017) and induces mast cell activation through the EP3 receptor signaling pathway, which enhances vascular permeability and promotes acute inflammation (Morimoto et al., 2014). This evidence concerns the gene PTGER2 and colorectal cancer.