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. Expression is particularly strong in liver, kidney and brain but is almost undetectable in heart. Belongs to the ERGIC family.