IDO1 and infection: Statistically significant protection from HIV-189.6 infection was observed compared to HIV-1 + Cc-Control with Cc-Elafin (57.5% protection TZM-bl cells; 73.4% protection PBMCs), Cc-BmKn2 (36.5% protection TZM-bl cells; 74.3% protection PBMCs), Cc-A1AT (37.7% protection TZM-bl cells; 48.3% protection PBMCs), Cc-Indo (44.8% protection) and Cc-Indo2 (44.9% protection) (Fig. 3a–d).