In this study, through a series of in vivo and ex vivo experiments using RBBP9-knockout mice (Rbbp9-/-), along with bioinformatic and histological analyses of human UC and CRC samples, we have identified RBBP9 as a negative regulator of inflammation and inflammation-induced tumorigenesis in the intestine. Here, RBBP9 is linked to colorectal carcinoma.