Because butyrate also showed HDAC inhibitor activity similar to propionate, we hypothesized that butyrate in BT Sup might be involved in the HECTD2-EHMT2-TNFAIP1 axis for growth suppression of colon cancer cell lines via the reduction of HECTD2 by inducing H3K27 acetylation, as shown by propionate treatment. This evidence concerns the gene HDAC9 and malignant colon neoplasm.