It is not expressed in healthy tissues, but it is significantly activated in inflammatory conditions, such as inflammatory diseases and cancers.57,58 Thus, S100A8/A9 is a potential biomarker of tissue inflammation and activation of proinflammatory cytokines.59 Lee et al.60 showed that X-ray irradiation markedly induces S100A8 expression in the hyperplastic epidermis of mice. The gene discussed is S100A8; the disease is cancer.