Our finding that MS patients had an overall increase in both monocyte number, IL10, CD274 and PDCD1LG2 during the 3rd trimester led us to speculate that endogenous type 1 interferons could be induced during pregnancy, since previous results have shown increased PDL1 and IL10 expression in monocytes after IFN-beta treatment (49), resulting in a strong anti-proliferative effect on CD4 T cells (32). Here, PDCD1LG2 is linked to myeloid sarcoma.