Increased CSF IL-10 level (cutoff values including: ≥0.43 pg/mL, ≥2 pg/mL, ≥4 pg/mL, ≥8.2 pg/mL, ≥8.3 pg/mL, ≥10.13 pg/mL, and ≥16.15 pg/mL) indicated poor PFS, facilitated discriminating PCNSL from systemic NHL and other CNS diseases (infection/inflammation, or other malignant tumors in CNS). The gene discussed is IL10; the disease is infection.