CD4 and toxic epidermal necrolysis: Only a minority of BF T cells was CD69+CD103+ (6,23% of total BF T cells, 6,91% of CD4+CD8+ BF T cells, Table 1), indicating that BF T cells did not represent “classical” long term Tissue Resident Memory T cells (TRM) of the epithelium [30], which have been previously implicated as potential triggers of tissue-specific restriction of symptoms in mucocutaneous diseases such as SJS/TEN [31].