GART and neoplasm: Adenomatous polyposis coli (APC), a classic tumor suppressor gene, has been shown to negatively regulate the Wnt signaling pathway via inhibiting β‐catenin expression.[55, 56] APCmin/+ mice have been widely studied and used as a spontaneous model of CRC.[57] Morphological observations revealed that an increased level of GART led to marked acceleration of tumor growth in the colorectum of APCmin/+ mice (Figure 6G; Figure S10, Supporting Information).