PTPRC and toxic epidermal necrolysis: To more deeply interrogate T cell subsets during active disease, we prospectively studied viable CD45+CD3+ T cells sorted from skin and blood using single-cell RNA-sequencing (scRNA-Seq) with cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) (37) along with T cell receptor sequencing (TCR-Seq) of 3 SJS/TEN patients, 3 MDE patients, and 3 healthy controls (Supplemental Table 3).