Next, we generated subcutaneous tumors with the MC38 cell line, a prevalent mouse gastrointestinal tumor model in immune‐competent C57 mice (Figure 4D, Figure S8C, D, Supporting Information), and our investigations showed that KDM3A knockout significantly inhibited tumor growth and tumor burden in vivo (Figure 5E,F), indicating that genomic or pharmacological inhibition of KDM3A could suppress tumor growth in vivo. Here, KDM3A is linked to digestive system neoplasm.