Thiol protease involved in a variety of inflammatory processes by proteolytically cleaving other proteins, such as the precursors of the inflammatory cytokines interleukin-1 beta (IL1B) and interleukin 18 (IL18) as well as the pyroptosis inducer Gasdermin-D (GSDMD), into active mature peptides. Plays a key role in cell immunity as an inflammatory response initiator: once activated through formation of an inflammasome complex, it initiates a pro-inflammatory response through the cleavage of the two inflammatory cytokines IL1B and IL18, releasing the mature cytokines which are involved in a variety of inflammatory processes. Cleaves a tetrapeptide after an Asp residue at position P1. Also initiates pyroptosis, a programmed lytic cell death pathway, through cleavage of GSDMD. Strict requirement for an Asp residue at position P1 and has a preferred cleavage sequence of Tyr-Val-Ala-Asp-|-. Heterotetramer that consists of two anti-parallel arranged heterodimers, each one formed by a 20 kDa (Caspase-1 subunit p20) and a 10 kDa (Caspase-1 subunit p10) subunit. Heterotetramer that consists of two anti-parallel arranged heterodimers, each one formed by a 20 kDa (Caspase-1 subunit p20) and a 10 kDa (Caspase-1 subunit p10) subunit. Can form a heterodimer with isoform epsilon which then has an inhibitory effect. Heterotetramer that consists of two anti-parallel arranged heterodimers, each one formed by a 20 kDa (Caspase-1 subunit p20) and a 10 kDa (Caspase-1 subunit p10) subunit. The two subunits are derived from the precursor sequence by an autocatalytic mechanism. Belongs to the peptidase C14A family.