The impact of greater production of TGF-β and TNF-α by DCs in response to probiotics during ageing is not clear; greater induction of TNF-α may be useful in initiating a pro-inflammatory response during infection, but dysregulation may be associated with autoimmunity and hyperinflammation (O'Shea et al., 2002; van Horssen et al., 2006; Ko et al., 2011). The gene discussed is TNF; the disease is infection.