sentence: We analyzed endogenous ARHGEF3 protein levels in 8 human nasopharyngeal cell lines by Western blotting and found that ARHGEF3 was overexpressed in 5 NPC cell lines ( CNE2 , SUNE1 , 5-8F , 6-10B and C666 ) , while the other 2 NPC lines ( CNE1 and HONE1 ) and the immortalized normal nasopharyngeal cell line NP69 exhibited low ARHGEF3 protein levels ( Figure 1A , left ) .