Corroborating our observations, alterations in the PI3K pathway such as enhanced basal pAKT, increased cytoplasmic FOXO and reduced PTEN activity, an antagonist of PI3K signaling, have been reported in the B cells of SLE patients, frequently presenting with an accumulation of CD21low B cells [61,65,66]. Here, PIK3CA is linked to systemic lupus erythematosus.