Table 2.

The mRNA expression of ANGPTL4 in NP tissues of different IVDD grades.

Pfirrmann grades	II	III	IV	V	r	P
n	4	44	65	8
ANGPTL4 mRNA expression (mean ± SD)	0.46 ± 0.09	0.58 ± 0.21	0.74 ± 0.24	0.81 ± 0.50	0.287	<0.001∗∗∗

n: sample size; r: correlation coefficient; SD: standard deviation. ^∗∗∗P < 0.001.