TNF and Alzheimer disease: Next, we determined whether mixed-species biofilms formed by S. aureus and A. alternata secrete factors that influence the expression of host variables associated with AD including thymic stromal lymphopoietin (TSLP) (known to be highly expressed in the skin of patients with AD and believed to activate downstream immune signals) (Komine, 2009) and pro-inflammatory cytokines (IL-18, IL-23, TNF-α) in keratinocytes (Werfel et al., 2016) (Figure 7).