Table 2. Associations between SOX9 expression and OS stratified according to the ethnics, case number, NOS score, follow-up time, antibody and cut-off value.

Categories	Subgroups	Ref	HR (95% CI)	Heterogeneity test (I2, P-value)
Ethnics	Asian Not Asian	[9, 10, 14, 16, 18, 19, 24, 32, 34–36, 38–40, 42]	1.98 (1.50–2.62)	53.8%, 0.009
			1.19 (0.96–1.48)	60.7%, 0.111
Case Number	≥ 100	[13,41]	1.60 (1.29–1.99)	71.8%, 0.000
		[9, 10, 18, 19, 24, 32, 34, 35, 38, 39, 42]
	< 100	[13, 14, 16, 36,40, 41]	2.05 (1.30–3.23)	0.0%, 0.770
NOS Score	≥ 7	[9, 10, 18, 34, 38, 40–42]	1.41 (1.10–1.79)	67.5%, 0.003
	< 7	[13, 14, 16, 19, 24, 32, 35, 36, 39]	2.69 (1.99–3.62)	46.4%, 0.071
Follow-up Time	≥ 120 m	[13, 16, 18, 19, 34, 35, 39]	2.26 (1.46–3.50)	78.0%, 0.001
	< 120 m	[9, 10, 14, 24, 32, 36, 38, 40–42]	1.53 (1.23–1.91)	67.1%, 0.001
Antibody	Santa Cruz	[13, 14, 16, 18, 34, 35, 38, 41]	1.58 (1.28–1.95)	74.0%, 0.001
	Millipore	[10, 24, 32, 36, 42]	1.54 (0.92–2.59)	41.1%, 0.147
	Abcam	[9, 39]	3.54 (2.11–5.94)	0.0%, 0.749
	Abnova	[19, 40]	1.63 (0.94–2.83)	0.0%, 0.573
Cut-off Value	IRS	[9, 14, 16, 32, 35, 36, 38, 42]	2.64 (1.67–4.17)	30.3%, 0.197
	PS	[13, 18, 24, 34, 40]	1.47 (0.99–2.18)	0.0%, 0.760
	Percentage	[10, 41]	1.13 (0.92–1.38)	0.0%, 0.844
	NR	[19, 39]	2.08 (1.37–3.16)	0.0%, 0.366

m: month; PS: Percentage Score; IRS: Immunoreactive Score; NR: Not Reported.