Studies with Fut4−/− and Fut7−/− hinted at a possible role for the host glycosylation machinery in TB.19,20 As Fut4 and Fut7 catalyse the terminal decoration of glycans, we reasoned that studying the impact of an earlier step of glycan biosynthesis would better reveal its biological effect during Mtb infection. The gene discussed is FUT4; the disease is tuberculosis.