In this study, to determine gene signatures in MTX-resistant PCNSL cells and PCNSL patients with poor prognoses, we conducted GSEA with NGS in PCNSL cell lines HKBML and TK and their MTX-resistant cells (HKBML-MTX and TK-MTX), and PCNSL tumor tissues. The gene discussed is TKT; the disease is neoplasm.