RACK1 and nasopharyngeal carcinoma: Moreover, Western blot analysis showed that RACK1 OE upregulated the expression of Bcl-2 and cyclin D, and downregulated the expression of Bax, cleaved PARP and p21, whereas RACK1 KD had the opposite effect on their expression (Fig. 3c), supporting the RACK1-induced-phenotype changes of NPC cell proliferation and apoptosis.