CD164 and systemic lupus erythematosus: CD164 (Endolyn), being a syalomucin enhancing sensitivity to CXCL12 when associated to CXCR432 and a human basophil activation marker33, was overexpressed on basophils from active SLE patients, which correlated with basopenia (Spearman r = −0.4165, P = 0.0029) (Table 1, Supplementary Fig. 2d–f).