NLRP1 and cyst: Because parasites lacking GRA35 also had a defect in tissue cyst formation in susceptible F344 rats, which possess a Toxoplasma-resistant variant of Nlrp1, and because F344 rat macrophages do not undergo pyroptosis in vitro, GRA35, like GRA42 and GRA43, must have an inflammasome-independent role in the pathogenesis of the parasite in vivo.