CD19 and systemic lupus erythematosus: Accordingly, Dorner and colleagues described increased levels of SHM in SLE from CD19 + B‐cells23, 50, 51 as well as CD27hi plasma cells.23 These authors also showed that the peripheral memory BCR repertoire in SLE is shaped by abnormal selection, increased SHM and increased receptor editing.52 In agreement with this, Sfikakis et al.53 showed increased levels of SHM in SLE.