IL4 and systemic lupus erythematosus: Consistent with the findings in the scleroderma-like cGVHD model, we found that the frequencies of TNF-ɑ-and IL-4-expressing CD4+T cells were significantly increased in the spleens of lupus-like recipients with IL-39 plasmid treatment (Additional file 1: Fig. S3B and S3C).