It has been demonstrated that overexpression of IFN-γ can result in eradication of PC in the absence of CD4+ T cell help (Kolls et al., 1999), in part through augmenting IFN-g–secreting type I (Tc1) CD8+ T cell response (McAllister et al., 2004). This evidence concerns the gene IFNG and pachyonychia congenita.