Additionally, Feng et al. [19] demonstrated that moderate overexpression of FTH1 did not affect nasopharyngeal carcinoma (NPC) cell growth with or without iron supplementation; moreover, the authors showed that the maximal overexpression of FTH1 decreased the cell growth rate in the absence of iron supplementation but that the cell growth rate remained unchanged in the presence of iron supplementation, which suggests that the expression level of FTH1 determined whether cell growth was affected. Here, FTH1 is linked to nasopharyngeal carcinoma.