Other abnormalities in the B cells of SLE patients include an imbalance in the number of B cell subtypes with an increase in memory B cells relative to naïve B cells, as well as an exaggerated B cell receptor (BCR) response with receptor cross-linking which leads to increased calcium influx and tyrosine phosphorylation of downstream signaling molecules [33]. Here, BCR is linked to systemic lupus erythematosus.