Marker genes for the identified T cell subtypes are shown in Figure 3L. To identify the nature of the IL-17+ T cells, we generated correlation plots between IL17A, CD4, and CD8A, revealing that CD4+ T cells and CD8+ T cells are likely both a source of IL17A in HS lesional skin (Figure 3, M and N). Here, CD4 is linked to histiocytic sarcoma.