Matsushita et al. (2009[15]) analyzed the same six PDE4D polymorphisms reported by Gretarsdottir et al. (2003[8]) in two large cohorts of patients with ischemic stroke, one cohort with 1112 patients and 1112 controls from Kyushu, Japan, and the other with 1711 patients and 1786 controls from BioBank Japan. The gene discussed is PDE4D; the disease is ischemic stroke.