Higher tumor uptake of [89Zr]Zr-BI 754111 observed in patients 1, 2, and 10 coincided with a higher CD4 and CD8 T-cell content and an activated T-cell signature at baseline, including relatively high expression levels of LAG-3 and other immune checkpoints, as well as evidence of increased Tregs and B-cells. The gene discussed is LAG3; the disease is neoplasm.