The enterotoxin acts on both healthy lymphocytes and lymphomatous cells, stimulating the secretion of cytokines (IL-2, IL-17, and IL-21) that activate the JAK-STAT3 and JAK-STAT5 pathways, which are hyperactive in CTCL [21, 24–26]. This evidence concerns the gene IL21 and primary cutaneous T-cell non-Hodgkin lymphoma.