Many of the proteins transmitted to the endoplasmic reticulum possess a sequence of 5 to 10 hydrophobic amino acids on their N-terminal end. Most of these proteins are transported from the ER to the cell's Golgi apparatus for processing and packaging. If they possess a certain retention sequence of 4 amino acids (KDEL; lys-asp-glu-leu) at their C-terminal end, however, the proteins normally will not leave the ER. In the instances where they do manage to exit the organelle, the proteins are redirected once they reach the KDEL receptors present in the Golgi apparatus. The Golgi apparatus was labeled in the digital video sequences of fox lung cells presented in this section with mEmerald and mitochondria were visualized with mCherry.