Given that PSGL-1 interaction with P-selectin induces Syk activation [13] and L-Selectin contributes to full activation of neutrophils, when interacting with P-selectin [33], we first studied the expression level of L-Selectin in the cell membrane and the level of pSyk in basal experimental conditions of neutrophils from HD and SLE patients. Here, SELP is linked to systemic lupus erythematosus.