Il15, Interleukin 15, is a cytokine belonging to the immunoregulatory cytokines family. It serves multiple functions, such as dictating T cell response, regulating tissue repair and B cell homing, modulating inflammation, and activating NK cells. IL-15 is unique due to its wide expression, tightly regulated secretion, trans-presentation, and therapeutic potential [3].

In cancer research, transgenic expression of IL15 and IL21 enhanced glypican-3-CAR T cells' antitumor properties against hepatocellular carcinoma, with increased proliferation related to TCF-1 upregulation [1]. IL15 synergizes with radiotherapy to reprogram the tumor immune contexture via a dendritic cell connection [2]. Exercise-induced engagement of the IL-15/IL-15Rα axis promotes anti-tumor immunity in pancreatic cancer [4]. In combination immunotherapy, IL15 with other agents like anti-CTLA-4 and anti-PD-L1 showed better effects in tumor-bearing mice, and clinical trials of such combinations are ongoing [5]. Also, co-expressing IL15 with CXCL10 in CAR-T cells enhances anti-tumor effects in gastric cancer [6]. Pretreatment with IL-15 and IL-18 rescues natural killer cells from granzyme B-mediated apoptosis after cryopreservation, improving their therapeutic feasibility [7].

In conclusion, Il15 is crucial for the activation and survival of anti-tumor effectors like CD8+ T and NK cells. Its role in enhancing T-cell expansion, survival, and function makes it a promising target in cancer immunotherapy. Studies on Il15 also contribute to understanding immune-related processes in autoimmunity, although anti-IL-15 therapies have not yet been successful in humans [8].