Upon P140 treatment (in vivo in MRL/lpr mice and ex vivo in SLE patients), we effectively observed a lower expression of MHCII molecules in antigen-presenting cells (APCs) that are mostly B cells in lupus (38), a weaker activity of autoreactive CD4+ T cells, and a lower number of plasma cells (17, 22, 25, 39, 40). The gene discussed is CD4; the disease is systemic lupus erythematosus.