IFNG and infection: These include IFNγ (Beatty et al., 1994a), sub-inhibitory concentrations of antibiotics (Engel, 1992; Wyrick and Knight, 2004), nutrient deprivation (Beatty et al., 1994a; Raulston, 1997; Harper et al., 2000), co-infection with either herpes simplex virus (Vanover et al., 2008; Prusty et al., 2012) or Toxoplasma gondii (Romano et al., 2013) in vitro, and infection with Chlamydia-phage (Hsia et al., 2000).