In a study by Skerry et al., to determine the role of probable TLR2 activating lipoproteins on mycobacterial-mediated HIV infectivity of CD4+ T cells, it was shown that the upregulation of M. bovis BCG lipoproteins, including LprF, LprH, LprI, LprP, LprQ, MPT83, and PhoS1, by M. smegmatis results greater ex vivo HIV infection of human PBMC CD4+ T cells. Here, CD4 is linked to HIV infectious disease.