The tail bleeding assay was rapid and facilitated the screening of the 21 CSS strains, and subsequently the identified strains were tested for arterial occlusion after the FeCl3 injury (Figure 7). The CSS-5 and CSS-17 had occlusion times similar to the B6 mice, but the doubly heterosomic CSS-5 × CSS-17 progeny had occlusion times higher than either the B6 mice or the heterosomic CSS-5F1 and CSS-17F1 or the A/J strains. In double heterosomic CSS-5 × CSS-17 mice, only one or three mice tested had occluded by 30 min; the other two mice did not occlude by 30 min. While only a small number of CSS mice have been tested for the arterial occlusion, the results suggest that interaction of the genes on chromosome 5 and 17 also determines arterial occlusion time.