To this end, Sfikakis and colleagues reported that lupus patients responding to rituximab downregulated CD40 ligand, CD69 and HLA-DR expression on CD4+ cells [29], while Tokunaga and colleagues reported downregulation of CD40 ligand, inducible costimulatory molecule (ICOS) and CD69 on CD4+-positive cells in patients (n = 3) with active systemic lupus erythematosus [30,31]. Here, CD40LG is linked to systemic lupus erythematosus.