PRF1 and cyst: This work showed that murine CNS cyst burden varied depending on neuron expression of a specific MHC I allele but did not determine if the changes in cyst burden arose from cytolytic clearance of infected neurons; induction of IFN-γ secretion by CD8+ T cells; or even non-cytolytic, perforin-dependent clearance of parasites by CD8+ T cells57.