Further functional evaluations of microglial VISTA in MS lesions revealed that VISTA has a differential expression in various stages of MS lesions, with the lowest expression during inflammation, and its knockout can stimulate morphological and transcriptional alterations toward an immune-activated and proliferative profile with amoeboid morphology and overexpression of genes involved in TNF and IFN signaling as well as the cell cycle. This evidence concerns the gene IFNA1 and myeloid sarcoma.