The zinc transporter ZIP9, also known as SLC39A9, is a member of a family of divalent ion transporters. Zinc is an essential ion for cells and plays significant roles in the growth, development, and differentiation. The zinc transporter family is divided into four subfamilies (I, II, LIV-1 and gufA). ZIP9 is a multipass membrane protein that belongs to the ZIP transporter subfamily I. It is located at the trans-Golgi network regardless of zinc presence and is thought to be a zinc homeostasis regulator acting in the secretory pathway without significantly altering cytosolic zinc homeostasis.