Possible role in transport between endoplasmic reticulum and Golgi. Positively regulates trafficking of the secretory proteins alpha1-antitrypsin/SERPINA1 and HP/haptoglobin (By similarity). Forms homodimers (By similarity). May form a heteromeric complex composed of ERGIC1, ERGIC2 and ERGIC3 (By similarity). Within the complex, the interaction with ERGIC1 is direct (By similarity). Interacts with ERGIC1/ERGIC32 (By similarity). Interacts with ERGIC2, the interaction is required for the stable expression of both proteins (By similarity). Interacts with MARCHF2 (By similarity). Interacts with SERPINA1/alpha1-antitrypsin and HP/haptoglobin (By similarity). Cycles between the endoplasmic reticulum and the Golgi. Belongs to the ERGIC family.