PRoleukin Observational Study to Evaluate the Treatment Patterns and CLinical Response in Malignancy (PROCLAIM), a US-based multicenter study designed to capture real-world clinical data for interleukin-2 in patients with metastatic melanoma, aRCC, or other malignancies showed that response after treatment with HD IL-2 was durable. This evidence concerns the gene IL2 and metastatic melanoma.