Precursor of a pore-forming protein that acts as a downstream mediator of granzyme-mediated cell death (PubMed:32299851). This form constitutes the precursor of the pore-forming protein: upon cleavage, the released N-terminal moiety (Gasdermin-B, N-terminal) binds to membranes and forms pores, triggering pyroptosis (PubMed:32299851). Pore-forming protein produced by cleavage by granzyme A (GZMA), which causes membrane permeabilization and pyroptosis in target cells of cytotoxic T and natural killer (NK) cells (PubMed:27281216, PubMed:32299851). Key downstream mediator of granzyme-mediated cell death: (1) granzyme A (GZMA), delivered to target cells from cytotoxic T- and NK-cells, (2) specifically cleaves Gasdermin-B to generate this form (PubMed:32299851). After cleavage, moves to the plasma membrane, homooligomerizes within the membrane and forms pores of 10-15 nanometers (nm) of inner diameter, triggering pyroptosis (PubMed:32299851). Binds to membrane inner leaflet lipids, such as phosphatidylinositol 4-phosphate, phosphatidylinositol 5-phosphate, bisphosphorylated phosphatidylinositols, such as phosphatidylinositol (4,5)-bisphosphate, and more weakly to phosphatidic acid (PubMed:28154144). Also binds sufatide, a component of the apical membrane of epithelial cells (PubMed:28154144). The full-length protein before cleavage is inactive: intramolecular interactions between N- and C-terminal domains mediate autoinhibition in the absence of activation signal (By similarity). The intrinsic pyroptosis-inducing activity is carried by the released N-terminal moiety (Gasdermin-B, N-terminal) following cleavage by granzyme A (GZMA) (PubMed:32299851). Homooligomer; homooligomeric ring-shaped pore complex containing 27-28 subunits when inserted in the membrane. Vesicular localization in the apical region of gastric chief cells and colonic surface mucous cells, and the basal region of neuroendocrine cells. Isoforms expression varies between tumor and non-tumor cells and changes in the regulation of isoforms transcription and translation may be seen in the development of gastrointestinal and hepatic cancers. In the gastrointestinal tract, expressed in proliferating cells, including in the basal cell layer of esophagus and in isthmus/neck of stomach. Expression is induced by interferon-gamma (IFNG). Intramolecular interactions between N- and C-terminal domains are important for autoinhibition in the absence of activation signal. The intrinsic pyroptosis-inducing activity is carried by the N-terminal domain. Cleavage by granzyme A (GZMA) relieves autoinhibition by releasing the N-terminal moiety (Gasdermin-B, N-terminal) that initiates pyroptosis (PubMed:32299851). Not cleaved by other granzymes (PubMed:32299851). Major cleavage site takes places after Lys-244; a minor cleavage site takes place after Lys-229 (PubMed:32299851). Long terminal repeat (LTR) of endogenous retrovirus HERV-H with reverse orientation may serve as alternative promoters of GSDML gene. Non canonical splice junctions. GSDML may be used as predictive markers of cervical lymph node metastasis and may help, with a panel of other genes, to discriminate between primary tumors of oral squamous cell carcinoma that metastasize to cervical lymph node and those that do not metastasize. Belongs to the gasdermin family.