2.8. Jurkat coculture and enzyme‐linked immunosorbent assay (ELISA) for interleukin (IL)‐2

MDA‐MB‐231 and MDA‐MB‐468 cells were treated with interferon (IFN)‐γ (300‐02, Peprotech, Rocky Hill, NJ, USA), and Jurkat cells were stimulated with 50 ng/L phorbol 12‐myristate 13‐acetate (PMA, P8139, Sigma‐Aldrich, Saint Louis, MO, USA) and 1 μg/mL ionomycin (I3909, Sigma‐Aldrich), both for 24 h. Next, 1 × 10⁴ TNBC cells/well were seeded in 96‐well plates. The supernatants were removed after the cells adhered, and Jurkat cells were added to TNBC cells at a ratio of 4:1 in 200 μL media. At 48 h later, the supernatants were collected and examined with a Human IL‐2 Valukine ELISA kit (VAL110, Novus, Littleton, CO, USA). The results were analyzed by ELISACalc V0.1 (Shanghai Bluegene Biotech Co. Ltd, Shanghai, China).