SLC7A6 and lysinuric protein intolerance: This finding is consistent with the occurrence in LPI patients of hemophagocytic lymphohistiocytosis (HLH), a disorder caused by an uncontrolled and self‐sustained cytokine‐driven immune activation of T lymphocytes and macrophages.25 We show here, in accordance with data by Werner et al,26 that CD3+ lymphocytes almost exclusively express SLC7A6; as a consequence, no alteration of arginine transport is expected to occur in LPI T lymphocytes.