Expression of CypA P29K also enhanced HIV-1 infection close to wild-type levels, while CypA P29D did not restore permissiveness to infection, possibly because the expression level of this mutant was too low in CypA-null Jurkat cells (approximately half of the expression level of wild type CypA in CypA-null Jurkat cells, Fig. 6b). The gene discussed is PPIA; the disease is HIV-1 infection.