CD98 heavy chain (CD98hc), expressed at high levels in developing human trophoblasts, is an integral membrane protein with multiple N-linked gly-cosylation sites and known to be important for cell fusion, adhesion, and amino acid transport. Western blotting and flow cytometry were used to study the effect of brefeldin A, an inhibitor of protein translocation through the Golgi, on CD98hc in the human placental trophoblast cell line BeWo.