F5 and Rare hereditary thrombophilia: In addition, rs4524 has been consistently associated with VTE in three large control-case studies (i.e., LETS, “Leiden Thrombophilia” study; MEGA-1 and MEGA-2, “Multiple Environmental and Genetic Assessment of Risk Factors for Venous Thrombosis” study) also after adjustment for FV Leiden, being the two variants in low linkage disequilibrium (r2 = 0.02) [48,49].