Used in immunotherapy research to enhance T cell and NK cell activation, supporting development of treatments for cancers and chronic viral infections. Acts as a soluble receptor complex to stabilize and prolong the half-life of interleukin-15 (IL-15), improving its bioavailability and signaling efficiency. Investigated for use in adoptive cell therapies and as an immune checkpoint modulator to boost anti-tumor responses. Also explored in vaccine adjuvants to strengthen cellular immunity.