Table 3 Summary of studies evaluating PD-L1 expression in primary CNS lymphoma

Berghoff et al [37].

Whole slide

Clone 5H1 (Abcam)

≥ 5% of tumor cells

Membranous

2/20 (10%)

Four et al [38].

Tissue microarray

Clone SP142 (Ventana)

≥ 1% of tumor cells

Membranous and cytoplasmic

12/32 (37.5%)

Hayano et al [39].

NA

Clone E1L3N (Cell Signaling Technology)

NA

Membranous

2/64 (4.1%)

Cho et al [40].

Tissue slide

Clone ab58810 (Abcam)

≥ 100 cells/HPF of tumor cells

NA

10/76 (13.2%)

Y Sugita et al [41].

Tissue slide

Clone EPR1161 (Abcam)

no staining (−);

0–30% (1+);

30–60% (2+);

>  60% (3+)

in both tumor cells and TAM

Membranous

12/17 (70.6%) in EBV- positive cases.

11/22 (50%) in EBV-negative cases.