Table 1. Summary of studies using miR-21 as a biomarker of lung carcinoma and study quality assessment.

First author	Year	patients (controls)	Racial	Disease	Cut-off	Normalizers	RNA extraction kits	Measurements	TP	FP	FN	TN	QUADAS scores
Hanbo Le et al. [22]	2012	82(50)	China	lung cancer	1.68 2−ΔΔCt	miRNA-16	miRNA extraction kit	TaqMan	38	4	44	46	13
Yanzhao Li et al. [32]	2011	20(10)	China	lung cancer	1.947 ng/ml	miRNA mimics	miRNA extraction kit	SYBR	16	0	4	10	12
Dongfang Tang et al. [33]	2013	96(122)	China	lung cancer	1.31	small nuclear U6B RNA	----	TaqMan	48	34	48	88	13
Bing Wang et al. [34]	2012	31(30)	China	lung cancer	3.63 2−ΔΔCt	miRNA-16	TRIzol	SYBR	27	8	4	22	13
Juan Wei et al. [30]	2011	77(36)	China	NSCLC	1.63 2−ΔΔCt	Cel-miR-39	miRNA extraction kit	SYBR	47	6	30	30	13
Amal A. et al. [35]	2013	65(37)	Egypt	lung cancer	2.441 ΔCt	miRNA SNORD68	miRNA extraction kit	SYBR	56	5	9	32	13
Hui Zhang et al. [36]	2012	129(83)	China	NSCLC (stageI, II)	1.101 2−ΔΔCt	Cel-miR-39	TRIzol	SYBR	100	12	29	71	13

Note: NSCLC: non-small cell lung cancer. TP: true positive. FP: false positive. FN: false negative. TN: true negative. QUADAS: The Quality Assessment of Diagnostic Accuracy Studies. ----: not reported in study.