These include granulysin, Fas ligand and, more recently, interleukin (IL)‐15.4, 5, 6 However, Nakajima et al. suggested that while granulysin and Fas ligand are possible candidate biomarkers,7 the duration of elevation is limited and therefore false‐negative results for SJS/TEN are a possibility. The gene discussed is FASLG; the disease is toxic epidermal necrolysis.