PBK and chordoma: In this study, we systemically investigated: (a) the expression of TOPK in chordoma patient tissues and cell lines; (b) the correlation of TOPK expression with patient clinicopathology and outcomes; (c) the function of TOPK in chordoma cell growth and proliferation; and (d) the effect of specific TOPK inhibitor on chordoma cell growth and proliferation in vitro and ex vivo three‐dimensional environment.