Likewise, the IGKV4-1 light chain gene has also been implicated in SLE and defects in B-cell tolerance [11], [18], [34] and a selective 3-fold loss of IGKV4-1 in peripheral B cells (HuMs-1 and -2 NSpl and HuMs-3 TSpl) relative to HuMs-ImmB BM cells (P<0.0001; χ2) was detected (Figure 4). The gene discussed is IGKV4-1; the disease is systemic lupus erythematosus.