CD274 and neoplasm: Interestingly, PDL1 expression was reported as negative in RMS2 (Fig. 4), RMS24, RMS18 (Additional file 2: Figure S1A and C) or a weakly expressed in RMS22 (Additional file 2: Figure S1E) in samples collected at diagnosis and first tumor progression, but it revealed to show a marked PD-L1 staining in the immune component both surrounding and infiltrating the tumor burden in the corresponding tissue obtained post therapy (Fig. 4 and Additional file 2: Figure S1B,D,F).