ABCG1 and viral infectious disease: RT-qPCR and immunoblotting indicated that HSV-1 decreased both the mRNA and protein levels of ABCA1 and ABCG1, whereas this decrease was restored by RA supplementation (Figures 5C–5E), thus suggesting that viral infection inhibited RA synthesis and consequently prevented ABCA1/G1-mediated lipid efflux.