Surprisingly, however, we failed to detect the HBV envelope beyond the ER, as it colocalized neither with ERGIC- nor Golgi-specific structures. Rather, the envelope accumulated in perinuclear ER regions in the form of a confined, crescent-shaped structure (CS). Since this structure was preserved even while interfering with the ER exit, provoked by Sec24A silencing or BFA treatment, the HBV envelope appears to be blocked in a pre-ERGIC compartment for much of its time in the cell. In contrast, the HBV subviral envelope has been shown to be transported out of the ER to the ERGIC where SVP assembly takes place. Hence, although both envelope types are dependent on COPII-guided transport events, the underlying mechanisms may not be thoroughly identical.