CD8A and melanoma: Farwell et al. [42] demonstrated, in phase 1 of the first in-human PET imaging research, the safety and possible predictive value of a [89Zr]Zr-labeled anti-CD8 mini-body in 15 patients with metastatic solid tumors (melanoma, NSCLC, and hepatocellular carcinoma) treated with immunotherapy (Figure 3).