CXCL8 and infection: A prior population-based study identified an association between poor oral health-periodontal disease and orodigestive cancer due to mono- or polymicrobial infection, which resulted in an increase in proinflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor alpha (TNFα), ultimately inducing gene expression relating to cell proliferation, for example, oncogenes [40].