Table 1. Descriptive characteristics of NPC patients and normal controls.

Characteristic	NPC patients	Normal controls
Sex (male:female)
Male	24	20
Female	16	14
Age (y, mean±SD)	49.3±15.2	33.4±14.5
Histology
Undifferentiated	40
Other	0
Primary tumor stage
T1	13
T2	15
T3	10
T4	2
Nodular metastasis
Yes	27
No	13
Distant metastasis
Yes	1
No	39