Some examples of those useful RNA are messenger RNA (mRNA) for arginase 1 (ARG1), lymphocyte antigen 96 (LY96), MMP9, s100 calcium-binding protein A12 (100A12), or chemokine receptor 7 (CCR7) for ischemic stroke [114]; CREM, ZAK, and PEI1 for cardioembolic stroke and atrial fibrillation detection [115]; and CCL3, CCL4, HLA-DRB3, IGHA1, IL8 to differentiate lacunar between non-lacunar stroke [116]. The gene discussed is MMP9; the disease is stroke disorder.