The role of C1q was examined further by Fonseca et al. (2004), who crossed AD mice model Tg2576 mice (APP mutation) with C1q−/− mice, giving rise to APPQ−/− mice which exhibited AD pathology but lacked C1q, and these mice were compared with APP mice [90,93,95,96]. The gene discussed is APP; the disease is Alzheimer disease.