CD4 and inflammatory bowel disease: In a similar gene-transfer approach, high IL-10 production is induced by lentiviral transduction into CD4+ T cells (CD4LV-IL10) to produce allogenic type 1 regulatory T cells (Tr1 cells) for “off-the shelf” GvHD and inflammatory bowel disease (IBD) treatment in clinical trials led by Tr1X Bio (31, 32).