ATF6 and HIV-1 infection: Notably, chronic METH (50 nM; blue bars) exposure significantly increased expression of UPR arm IRE1α by 50% (p < 0.05) without increasing BiP, ATF6, or PERK (Figure 3G), and HIV-1 infection (500 RT; red bars) induced significant increases in all arms and their binding partner (p < 0.05) (Figure 3H).