Cal-1 reduced CCR5 expression in PBMCs to CCR5Δ32 heterozygote levels and suppressed virus up to day 12. No escape mutations were present through 9 weeks of challenge. Cal-1 suppressed infection by different R5 viruses and inhibited virion internalization by 70% compared to 13% for C46 (166). The gene discussed is CCR5; the disease is infection.