FASLG and toxic epidermal necrolysis: However, M. pneumoniae has also been isolated from skin blisters by multiple independent investigators raising the possibility of cutaneous infection.13, -15 At the cellular level, Fas ligand (FasL)–mediated epidermal apoptosis and cytotoxic T-cell-mediated cell death have both been reported in SJS and TEN.16 The wide range of skin presentation and the multiple mechanisms reported suggest a complex interaction between host- and pathogen-dependent factors.