Biodistribution data showed that uptake in the tumor with low CD25 expression was only 1.4 ± 0.4%ID/g, which is lower than Ab blocked 89Zr-CD25 IgG uptake and 89Zr-labeled IgG2a isotype IgG uptake in SUDHL1 tumors. The gene discussed is IL2RA; the disease is neoplasm.