To address this matter, we compared the immunomodulatory effects of pregnancy on five leukocyte populations (i.e., CD4+ and CD8+ T cells, CD4+CD127−CD25high regulatory T cells, CD56brightCD16− NK cells, and CD14+CD163+ monocytes) in peripheral blood from different cohorts of MS patients and healthy women at different times of gestation, as well as in decidual samples from the placenta of MS patients and healthy women collected after delivery. This evidence concerns the gene CD4 and myeloid sarcoma.