NPC-associated fibroblasts, stromal cells and inflammatory cells produced IL6, likely resulting in increased IL6 in sera of NPC patients; some of these tumors also demonstrated increased expression of IL6 receptor, thereby enhancing STAT3 activation (Ma et al., 2008; Tsang et al., 2013; Zhang et al., 2013). This evidence concerns the gene IL6 and nasopharyngeal carcinoma.