HDAC4 and nasopharyngeal carcinoma: Furthermore, we examined the mRNA and protein levels of HDAC4 by qRT-PCR and western blotting in NP69 cells and four other cell lines (S18 and S26; 5-8F and 6-10B, derived from the NPC cell lines CNE2 and Sune1 and exhibiting high and low metastatic ability, respectively)4 (Fig. 1E).