CD40LG and deep vein thrombosis: He had a past history of extensive deep vein thrombosis (DVT) in the lower right limb about 5 years earlier, and as he did not have any provoking factors, thrombophilic tests was checked and showed negative results (antithrombin III, factor V Leiden, lupus anticoagulant, and anti‐cardiolipin IgG and IgM).