CD38 and systemic lupus erythematosus: We observed (Figure S3 in Text S1) that proliferation marker Ki-67 and activation markers CD69, HLA-DR and CD38 were up-regulated on CD8+ T cells from SLE patients as previously reported.[20], [27], [28] Taken together, this demonstrates that T cell hyper activation and hyper proliferation are essential factors in SLE pathophysiology.