Flow cytometry detected numerically higher numbers of peripheral blood lymphocyte (CD45+, CD3+, CD3+ CD4+ and CD3+ CD8+ T cells) counts and a numerically lower proportion of Treg cells among patients with CB than among those with NB at baseline (P > 0.05), and numerically higher numbers of peripheral blood lymphocyte counts and CD69+ T cells, and numerically lower proportions of Treg cells, PD-1+ T cells and LAG-3+ T cells among patients with CB than among those with NB at C3D17 (P > 0.05). Here, PDCD1 is linked to neuroblastoma.