Corrigendum: Coexpression of HHLA2 and PD-L1 on tumor cells independently predicts the survival of spinal chordoma patients - Xia, Chao; Huang, Wei; Chen, Yun-Liang; Fu, Hai-Bin; Tang, Ming; Zhang, Tao-Lan; Li, Jing; Lv, Guo-Hua; Yan, Yi-Guo; Ouyang, Zhi-Hua; Yao, Nvzhao; Wang, Cheng; et al. (Frontiers in Immunology, 2023)