IL2 and metastatic melanoma: In a phase Ib clinical study, Munoz-Cosuelo et al. evaluated the combination of fibroblast activation protein interleukin-2 variant (FAP-IL2v), a novel immunocytokine engineered to address the limitations of wild-type IL-2, with the checkpoint inhibitor pembrolizumab in patients with advanced or metastatic melanoma, including both checkpoint inhibitor (CPI)-naïve and CPI-experienced individuals.