A method for increasing the transduction efficiency of cells cultured with a lentivirus comprising: culturing the cells and the lentivirus in a culture medium that comprises a compound that increases prostaglandin EP receptor signaling, wherein the cells are cultured with the lentivirus during, or prior to, culture with the compound that increases prostaglandin EP receptor signaling wherein (a) the compound that increases prostaglandin EP receptor signaling is selected from the group consisting of: PGA2; PGB2; PGD2; PGE1; PGE2; PGF2; PGI2; PGH2; PGJ2; and analogues thereof; (b) the compound that increases prostaglandin EP receptor signaling is selected from the group consisting of: 15d-PGJ2; delta12-PGJ2; 2-hydroxyheptadecatrienoic acid; Thromboxane A2; Thromboxane B2; Iloprost; Treprostinil; Travoprost; Carboprost tromethamine; Tafluprost; Latanoprost; Bimatoprost; Unoprostone isopropyl; Cloprostenol; Oestrophan; Superphan; Misoprostol; Butaprost; Linoleic Acid; 13(s)-HODE; LY171883; Mead Acid; Eicosatrienoic Acid; Epoxyeicosatrienoic Acid; ONO-259; Cay1039; a PGE2 receptor agonist; 16,16-dimethyl PGE2; 19 -hydroxy PGE2; 16,16-dimethyl PGE2 p-(pacetamidobenzamido) phenyl ester; 11-deoxy-16,16-dimethyl PGE2; 9-deoxy-9-methylene-16,16-dimethyl PGE2; 9-deoxy-9-methylene PGE2; Sulprostone; PGE2 serinol amide; PGE2 methyl ester; 16-phenyl tetranor PGE2; 15 -15-methyl PGE2; 15 -15-methyl PGE2; BIO; 8-bromo-cAMP; Forskolin; Bapta-AM; Fendiline; Nicardipine; Nifedipine; Pimozide; Strophanthidin; Lanatoside; L-Arg; Sodium Nitroprusside; Sodium Vanadate; Bradykinin; Mebeverine; Flurandrenolide; Atenolol; Pindolol; Gaboxadol; Kynurenic Acid; Hydralazine; Thiabendazole; Bicuclline; Vesamicol; Peruvoside; Imipramine; Chlorpropamide; 1,5-Pentamethylenetetrazole; 4-Aminopyridine; Diazoxide; Benfotiamine; 12-Methoxydodecenoic acid; N-Formyl-Met-Leu-Phe; Gallamine; IAA 94; and Chlorotrianisene; or (c) the compound that increases prostaglandin EP receptor signaling is selected from the group consisting of: prostaglandin E2, or 16,16-dimethyl PGE2. (a) the compound that increases prostaglandin EP receptor signaling is selected from the group consisting of: PGA2; PGB2; PGD2; PGE1; PGE2; PGF2; PGI2; PGH2; PGJ2; and analogues thereof; (b) the compound that increases prostaglandin EP receptor signaling is selected from the group consisting of: 15d-PGJ2; delta12-PGJ2; 2-hydroxyheptadecatrienoic acid; Thromboxane A2; Thromboxane B2; Iloprost; Treprostinil; Travoprost; Carboprost tromethamine; Tafluprost; Latanoprost; Bimatoprost; Unoprostone isopropyl; Cloprostenol; Oestrophan; Superphan; Misoprostol; Butaprost; Linoleic Acid; 13(s)-HODE; LY171883; Mead Acid; Eicosatrienoic Acid; Epoxyeicosatrienoic Acid; ONO-259; Cay1039; a PGE2 receptor agonist; 16,16-dimethyl PGE2; 19 -hydroxy PGE2; 16,16-dimethyl PGE2 p-(pacetamidobenzamido) phenyl ester; 11-deoxy-16,16-dimethyl PGE2; 9-deoxy-9-methylene-16,16-dimethyl PGE2; 9-deoxy-9-methylene PGE2; Sulprostone; PGE2 serinol amide; PGE2 methyl ester; 16-phenyl tetranor PGE2; 15 -15-methyl PGE2; 15 -15-methyl PGE2; BIO; 8-bromo-cAMP; Forskolin; Bapta-AM; Fendiline; Nicardipine; Nifedipine; Pimozide; Strophanthidin; Lanatoside; L-Arg; Sodium Nitroprusside; Sodium Vanadate; Bradykinin; Mebeverine; Flurandrenolide; Atenolol; Pindolol; Gaboxadol; Kynurenic Acid; Hydralazine; Thiabendazole; Bicuclline; Vesamicol; Peruvoside; Imipramine; Chlorpropamide; 1,5-Pentamethylenetetrazole; 4-Aminopyridine; Diazoxide; Benfotiamine; 12-Methoxydodecenoic acid; N-Formyl-Met-Leu-Phe; Gallamine; IAA 94; and Chlorotrianisene; or (c) the compound that increases prostaglandin EP receptor signaling is selected from the group consisting of: prostaglandin E2, or 16,16-dimethyl PGE2.