A concise overview of the first-in-human study of a no-alpha interleukin-2 (IL-2) mutein in patients with advanced solid tumors. The episode covers the rationale for avoiding IL-2 receptor alpha (CD25) to spare regulatory T cells, the phase I dose-escalation design, safety and pharmacodynamic findings showing selective activation of CD8+ T cells and NK cells, and the preliminary clinical signals. We discuss the implications for pharmacists and physicians, including dosing considerations, safety monitoring, and future study directions, with attention to limitations such as small sample size and lack of a control arm.