In 1945, K. R. Porter et al. observed mouse embryonic fibroblasts (MEFs) and found that the cytoplasmic part of the cell had an unreported reticular structure, so it was named endoplasmic reticulum (ER). The major functions of the endoplasmic reticulum are: synthesis of intracellular proteins and the modification and processing of proteins. It is an important organelle in eukaryotic cells. It is a three-dimensional network structure in which complex and closed intracellular tubular intimal systems are intertwined. When cells are subjected to va...