CD274 and chordoma: (94) performed multi-omics sequencing including WGS, RNA-seq, and WGBS and successfully identified a recurrent pediatric poorly differentiated chordoma with features of single copy losses affecting SMARCB1, hypomethylation of the TBXT promoter, overexpression of the Brachyury tumor antigen and CD274 (PD-L1), and CD8+ T-cell, CD79a+ B-cell, and plasma cell infiltration.