F8 and systemic lupus erythematosus: Within pro-coagulant factors the largest RRRs, indicative of a larger effect on IS than on MI, were observed for FV Leiden mutation (RRR 3.42, 95% CI 0.11–104), a genetic variant in the gene coding for coagulation factor VIII (F8 rs6655259, RRR 4.72, 95% CI 0.62–35.73), presence of lupus anti-coagulant (RRR 8.13, 95% CI 0.61–108.76) and three variants of FXIII (F13A1 V34L, RRR 4.66, 95% CI 0.44–49.10; F13A1 T204P, RRR 11.1, 95% CI 5.64–21.82 and F13A1 rs3024462, RRR 3.71, 95% CI 0.62–22.35).