a, Coomassie Blue-stained SDS-PAGE gel showing recombinant engineered GSDMA with Flag tag-3C protease cleavage sequence inserted immediately after residue G214, Q246, treated with 3C protease. b–d, 293T cells were transfected with the indicated plasmids (Empty vector or Flag-tagged Gasdermin) before cell death was observed by phase-contrast microscopy (b) and determined by LDH release assay (c), whole cell lysates were collected for immunoblot analysis (d). Arrowheads indicate pyroptotic cells; Scale bar: 10 μm. Graphs show mean ± s.d. of triplicate wells. c, Two-tailed Student’s t-test. Data are representative of at least three independent experiments. For gel source data, see Supplementary Fig. 1.