To further examine altered ER physiology and ER-associated signaling pathways in response to METH exposure and HIV-1 infection, protein expression of the three UPR arms (ATF6, IRE1α, and PERK), along with their classical ER stress negative regulating binding partner, BiP, was determined using Simple Wes (Figures 3E–H). Here, ATF6 is linked to HIV-1 infection.