FASLG and toxic epidermal necrolysis: Nevertheless, one study showed that sera of SJS/TEN were able to induce abundant keratinocyte apoptosis and furthermore that peripheral blood monuclear cells of patients stimulated by the causative drug excreted high levels of sFasL [50], but it should be noted that sera can contain small membrane vesicles with membarne bound FasL that can account for the observed activity.