Final answer:
Proteins exiting the ER will generally go to the Golgi apparatus next.
Step-by-step explanation:
Proteins exiting the endoplasmic reticulum (ER) will generally go to the Golgi apparatus next. Transport vesicles leaving the ER fuse with a Golgi apparatus on its receiving, or cis, face. The proteins are processed within the Golgi apparatus, and then additional transport vesicles containing the modified proteins and lipids pinch off from the Golgi apparatus on its outgoing, or trans, face. These outgoing vesicles move to and fuse with the plasma membrane or the membrane of other organelles.