Recent studies on relation extraction have shown that by combining kernels with Support-vector Machines (SVM), one can obtain results superior to feature-based methods (Bunescu and Mooney, 2005b;<cite> Bunescu and Mooney, 2005a</cite>; Culotta and Sorensen, 2004; Cumby and Roth, 2003; Zelenko et al., 2003; Zhang et al., 2006a; Zhang et al., 2006b; Zhao and Grishman, 2005) .