PARP1 is shown to activate JNK and DNA binding of AP-1 in fibroblasts (23) and enhance NF-κB/AP-1 binding to MMP9 promoter sequence in diabetic retinopathy (24), though its role in transcriptional activation of the profibrotic program in Mφ, if any, is not known. This evidence concerns the gene FOSB and diabetic retinopathy.