Expression of PTK6 in cell lines and nasopharyngeal tissues. (A) PTK6 expression was higher in most of NPC cell lines include CNE1, CNE2, 6-10B, 5-8F, HONE1 and SUNE1 than in Bmi-1/NPEC1 and Bmi-1/NPEC2 by Western blot analysis. (B) Quantitative analysis of PTK6 protein as mean (±SD) by normalizing to the expression of GAPDH. n=three different experiments. (C) Quantitative RT-PCR detection showed that in those 6/7 NPC cell lines presented higher mRNA expression level of PTK6 than that in those two NPECs. n=three independent experiments. (D) The mRNA expression levels of PTK6 from 31 NPC patients and 16 non-tumorous tissues were determined by quantitative RT-PCR (P= 0.033).