In the study, we investigated the expression feature of KMT2A in gastric cancer through analyzing the public cancer TCGA dataset and detecting the clinical samples and found the significantly higher expression of KMT2A in gastric cancer; then, the prognostic value of KMT2A was further assessed, and it was demonstrated that high expression of KMT2A was associated with worse prognosis (OS and PFS). The gene discussed is KMT2A; the disease is gastric cancer.