CD274 and neuroblastoma: The expression of HLA-G, PD-1, and PD-L1 was similar when we compared M-stage (3.95 ± 5.00, 5.36 ± 2.71 and 56.97 ± 35.22, respectively) and L-stage (3.41 ± 0.93, 4.41 ± 3.09 and 43.73 ± 13.10, respectively) NB patients (Figure 3B).