Table 3. Stability ranking of 10 RGs determined by GeNorm, NormFinder and BestKeeper.

Rank	geNorm		NormFinder		BestKeeper
	Gene	M-value	Gene	S-value	Gene	SD	CV
1	Tbp	0.0150	Hprt	0.0467	Rps29	0.1788	0.8372
2	Rps18	0.0159	Rps18	0.0533	Rps18	0.1888	0.8762
3	Hprt	0.0155	Ubc	0.0574	Ubc	0.2002	0.9364
4	Sdha	0.0167	Sdha	0.0582	Rpl13a	0.2047	0.8533
5	Rpl13a	0.0170	Rpl13a	0.0594	Sdha	0.2358	0.9812
6	Ubc	0.0174	Tbp	0.0611	Tbp	0.2375	0.8120
7	Rps29	0.0189	Gapdh	0.0624	Hprt	0.2552	1.0255
8	Gapdh	0.0195	Rps29	0.0699	B2m	0.2726	1.2001
9	B2m	0.0220	Actb	0.0770	Gapdh	0.2868	1.3808
10	Actb	0.0231	B2m	0.0813	Actb	0.3234	1.5939

Note:

Ranking is depicted in descending order, so that 1 is most stable and 10 is least stable. geNorm calculates an average expression stability (M-value), with a cut-off value of <0.5 for relatively homogenous samples. NormFinder calculates relative expression stability (S-value), also with a cut-off of <0.5. BestKeeper calculates standard deviation (SD) and coefficient of variance (CV), with a SD cut-off of <1.0.