However, as shown in Table 1, anti-CD25 antibody treatment did not result in tumor growth inhibition (Fig. 1B), nor improve the anti-PD-1 efficacy (Fig. 3A) in Hepa 1–6 tumors, which likely resulted from that CD25 antibody targets CD4+ effector cells as well as Treg, a Treg specific response could not be delineated with this method. Here, PDCD1 is linked to neoplasm.