Possible role in transport between endoplasmic reticulum and Golgi. Positively regulates trafficking of the secretory proteins SERPINA1/alpha1-antitrypsin and HP/haptoglobin (PubMed:31142615). Forms homodimers (PubMed:31142615). May form a heteromeric complex composed of ERGIC1, ERGIC2 and ERGIC3 (PubMed:31142615). Within the complex, the interaction with ERGIC1 is direct (PubMed:31142615). Interacts with ERGIC1/ERGIC32 (PubMed:15308636, PubMed:31142615). Interacts with ERGIC2, the interaction is required for the stable expression of both proteins (PubMed:31142615). Interacts with MARCHF2 (PubMed:31142615). Interacts with alpha1-antitrypsin/SERPINA1 and HP/haptoglobin (PubMed:31142615). Cycles between the endoplasmic reticulum and the Golgi. Belongs to the ERGIC family.