CD19 and systemic lupus erythematosus: In order to dissect the heterogeneity of the polyclonal set of anti-NETs antibodies in the serum from SLE patients, we cloned 206 humAbs from single plasmablasts (CD3−, CD20−, CD19+, CD27hi, CD38hi) sorted from PBMC of two active SLE patients with renal disease (Table 1, Supplementary Fig. 2).