CCR5 and HIV-1 infection: As HIV-1 infection of target cells is a multistep process starting with attachment of viral glycoproteins (gp120/gp41) to host cell receptors (CD4 and CCR5 or CXCR4), fusion of viral envelope, reverse transcription, integration, and maturation of virions by killing target cells [21], it will be interesting to understand which of these steps are affected by treatment with 405 nm light, and this will be the focus of future studies.