Transient CD19 masking with tafasitamab decreases tumor cell pyroptosis. (A) In vitro high-mobility group box 1 (HMGB-1) assay. CART19, CD19⁺JeKo-1, and increasing doses of tafasitamab (10-400 μg/mL) or the isotype control were cultured for 24 hours. Cells were processed with the Lumit HMGB1 immunoassay kit (mean ± SEM, ∗P < .05, ∗∗∗P < .001, 1-way ANOVA; n = 2, 2 replicates). (B) Western blot of tumor cells on day 1. Satellite mice were euthanized and their spleens were harvested. Tumor cells were then isolated with CD20 micro beads from splenic cells. The expression of GSDME was determined using western blot (n = 3 per group).