While our finding of reduced circulating magnesium levels in sporadic NPC cases compared to controls does not directly implicate NIPAL1, our findings take on added significance when considered in light of the recent discovery that null mutations in another magnesium transport gene, MAGT1, which abrogates magnesium flux in NK and CD8 T cells, predisposes to uncontrolled EBV infection and EBV-associated lymphomas11,21. Here, MAGT1 is linked to Epstein-Barr virus infection.