Fig 1: Expression of COL4A3 and the deposition of collagen fibers in NPC. (A and B) The expression of COL4A3 in the downward progressing type of NPC was significantly lower compared with that in upward progressing type of NPC. *P<0.05. (C and D) The deposition of collagen in the downward progressing type of NPC was significantly lower compared with that in the upward progressing type of NPC. *P<0.05. (E) The association between the expression level of COL4A3 and the prognosis of head and neck squamous cell carcinoma using the Kaplan-Meier plotter database found that the high expression level of COL4A3 was associated with good prognosis (hazard ratio, 0.69; 95% CI, 0.49–0.97; P=0.031). NPC, nasopharyngeal carcinoma.