We found that knocking down endogenous CTGF expression not only elevated the expression of PCNA (Figure 3A) but also sped up cell proliferation (Figure 3B) and the G1/S transition in NPC 6–10B and HONE1 cells(Figure 3C), compared to their respective Si-Ctr-treated NPC cells. This evidence concerns the gene PCNA and nasopharyngeal carcinoma.