Summary of studies using miR-21 as a biomarker of GC and study quality assessment. ZengZongyue WangJiangen ZhaoLiuyang HuPing ZhangHailong TangXi HeDali TangShifu ZengZhaofang 2013 <p>Note: *Calculated from independent patient data (IPD) QUADAS = quality assessment for studies of diagnostic accuracy. AUC = Area under the curve of a receiver operator curve. NR = not report. Se = sensitivity. Sp = specificity.</p>