IL2 and neoplasm: In addition, the supernatant levels of T cell‐derived cytokines interleukin‐2 (IL‐2) and interferon‐γ (IFN‐γ) were remarkably upregulated in B3Z T cells cocultured with RA‐pretreated tumor cells (Figure 2B,C), concurrently accompanied with increased expression level of T cell activation marker CD69 (Figure 2D).