<h4>Objective</h4>Magnesium transporter 1 (MAGT1) plays a crucial role in magnesium homeostasis and immune regulation, yet its clinical significance and functional role in breast cancer remain largely unexplored.<h4>Methods</h4>The expression pattern and prognostic value of MAGT1 in breast cancer were analyzed using data from The Cancer Genome Atlas (TCGA) and validated by immunohistochemistry on a tissue microarray comprising 60 patient samples. The gene discussed is MAGT1; the disease is breast cancer.