X-linked immunodeficiency with magnesium defect, Epstein-Barr virus (EBV) infection and neoplasia (XMEN) disease is caused by hemizygous loss of function (LOF) gene variants in MAGT1. MAGT1 is a plasma membrane transporter of magnesium (Mg2+) that plays a relevant role in immune responses and acts as a second messenger in intracellular signaling, but also it is involved in the glycosylation of proteins. Here, MAGT1 is linked to neoplasm.