PDCD1 and rhabdomyosarcoma: In alveolar rhabdomyosarcoma, PD-L1+ and PD-L1+CD8+ tumors significantly correlated with low IRS grade (p = 0.005; p = 0.033), whereas PD-1+, PD-1+PD-L1+, PD-1+CD8+ and PD-1+PD-L1+CD8+ tumors showed a trend towards a low IRS grade (p = 0.071).