DNMT3A overexpression was detected in human GC specimen and associated with bad overall survival of patients. Gastric adenomas of our gp130FF, A33Dnmt3a mouse model have a 10-fold elevated Dnmt3a expression. Importantly, tumour‑specific Dnmt3a overexpression significantly increased gastric tumour burden. In the KPT model, we have identified DNMT3A as being highly expressed in the invasive front of tumours, their liver metastases as well as in the allograft tumours established by the KPT organoids. In this model of advanced gastric cancer, treatment with the DNMT inhibitor decitabine significantly decreased tumour growth...