Identification and Validation of Common Reference Genes for Normalization of Esophageal Squamous Cell Carcinoma Gene Expression Profiles

Table 1

Evaluation of the expression stability of the eight candidate internal reference genes by NormFinder.

Rank number	Cancer esophageal tissues		Normal esophageal tissues		All esophageal tissues
	Gene in ranking order	Stability value	Gene in ranking order	Stability value	Gene in ranking order	Stability value
1	PPIA	0.51	RPS18	0.65	GAPDH	0.15
2	RPS18	0.64	PPIA	0.84	PPIA	0.19
3	ACTB	0.77	B2M	1.00	ACTB	0.25
4	PGK1	0.94	HPRT1	1.31	B2M	0.4
5	GAPDH	0.96	GAPDH	1.40	HPRT1	0.56
6	B2M	1.13	ATCB	1.82	RPS18	0.74
7	HPRT1	1.17	GUSB	2.17	GUSB	0.87
8	GUSB	1.54	PGK1	3.23	PGK1	1.03

Note: The lower the SV, the higher the stability.