LAG3 expression in DLBCL (A) Case 1. LAG3 (brown) staining in PAX5⁻ TILs (arrows). PAX5 (red) nuclear staining highlights B cells (original magnification ×40). (B) Case 2. Malignant B cells (arrows) show LAG3 expression (PAX5⁺/LAG3⁺) (original magnification ×40). (C) Patients with LAG3⁺ DLBCL cells by IHC had significantly higher total LAG3 mRNA gene counts in their diagnostic biopsies.