Investigating this hypothesis, the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) study was an observational study of IV tPA-treated patients for which target perfusion–diffusion mismatch was defined as mismatch volume (PWI–DWI) > 10 cm3 or mismatch ratio (PWI/DWI) > 1.2. The gene discussed is PLAT; the disease is Stroke.