STAT3 phosphorylation, IL-2R subunits expression, and proliferation of primary CTCL (SS) cells in the presence of SE. (A) STAT3 phosphorylation in malignant and nonmalignant T cells from cultured SS PBMC cultures in the presence of SE (ie, cultures of malignant T cells and bystander cells from 2 patients). Data from 5 additional patients are shown in supplemental Figure 4. (B) IL2R-α, IL2R-β, and IL2R-γ expression in primary malignant and nonmalignant T cells from cultured SS PBMCs in the presence of SE after 3, 6, and 12 days as described previously. (C) Proliferation of primary malignant T cells from cultured SS PBMCs in the presence or absence of SE after 3, 6, and 12 days. Data in panels B and C are representative of 2 patients. PBS, phosphate-buffered saline; SE, staphylococcal enterotoxin; US, unstimulated.