BLK and systemic lupus erythematosus: An analysis of RNA-seq data from two independent studies (Accession ID: GSE118254 and GSE92387, Supplementary file 1) consistently showed that expression patterns for two representative genes (BLK and FDFT1) are gradually increased in a developmental process from naive to memory B cells, in particular, the double negative memory B cell subset in patients with SLE, the pattern that is not observed in controls (Figure 2—figure supplements 2 and 3).