Updated publication reference for PubMed record(s): 29915147, 28679634. Here we used a newly identified Sec61 blocker, mycolactone, to analyze Sec61 contribution to antigen cross presentation, ERAD and transport of internalized antigens into the cytosol in dendritic cells. Shotgun proteomics were used to asses the broad-ranging effects of Sec61 blockade on dendritic cells and its effect on critical proteins required for antigen presentation and ERAD.