MTHFR and Venous thrombosis: Among the venous thrombosis related genes (Fig 2B), FV(Leiden), MTHFR(A1298C) and FXIII(V34L) were significantly related to the prominence of the co-expression of the mutated alleles Del/4G(+/+) [(0%, 50.0%, 83.3%, versus 20.4%, 63.7%, 38.1%) (Del/4G(-/-) versus (+/+)), respectively].