Table 1. mRNA expression levels of MMP-9, MMP-2, NGAL and TIMP-1 in AVMs and normal tissues.

Gene	Sample	Mean ± SD	Min Value	Max Value	Median	P Value
MMP-9	AVM	2.10 ± 1.93	0.03	5.78	1.60	P < 0.05
	Normal	0.58 ± 0.32	0.09	1.00	0.60
MMP-2	AVM	1.28 ± 0.81	0.43	3.01	1.01	P > 0.05
	Normal	2.28 ± 2.72	0.52	8.83	1.00
NGAL	AVM	0.87 ± 1.63	0.04	5.71	0.18	P > 0.05
	Normal	0.92 ± 1.29	0.03	3.77	0.48
TIMP-1	AVM	6.39 ± 5.56	1.27	21.93	5.08	P < 0.05
	Normal	1.08 ± 0.91	0.29	3.30	0.76