Taking into consideration that levels of membrane-associated sialic acid increase during in vitro mono-DC differentiation32, the elevated sialic acid levels in SLE blood33, and that a strong pro-inflammatory environment exists in both settings, we investigated patterns of CD33/LAIR-1 expression on mono-DCs and SLE blood myelomonocytes. This evidence concerns the gene CD33 and systemic lupus erythematosus.