(A–D) Immunoblot analysis of changes in cleaved ATF6, XBP1s, phosphorylated EIF2S1 (p-EIF2S1), and total EIF2S1 protein levels following treatment with the indicated time points and concentrations of sodium arsenite in NIH 3T3 (A), HeLa (B), HEK 293 (C), or HEMn-LP (D) cells. Starvation (HBSS), or 0.1 µM BAF for 2 or 4 h were used as controls. GAPDH was used as an internal loading control.