Combined with the previous literature and the results of single-cell sequencing analysis, it is suggested that the expression of GPX1 and RCN1 in microglia and pericytes may regulate endoplasmic reticulum stress through the APP–CD74 pathway, thereby further affecting the progression of MS, while also identifying specific subtypes of microglia and their biological functions. This evidence concerns the gene GPX1 and myeloid sarcoma.