ABCA1 and HIV infectious disease: It has been demonstrated in vitro that HIV infection via negative regulatory factor (Nef) protein harms the monocyte-macrophage cholesterol efflux by increasing the degradation of the ATP-binding cassette transporter-A1 (ABCA1), a crucial transporter of lipids and cholesterol from cells to extracellular apolipoprotein-A1 [102], but by up-regulating its mRNA [103].