Several transcription factors have been suggested to control ENPP2/Enpp2 transcription in different cell types and pathophysiological states: Hoxa13 and Hoxd13 in mouse embryonic fibroblasts (21), v-jun in chick embryo fibroblasts (22), c-jun in soft tissue sarcomas (23), Stat3 in breast cancer cells (24), AP-1 in keratinocytes and neuroblastoma cells (25, 26), NFAT1 in melanoma and carcinoma cells (27, 28), as well as NF-kB in keratinocytes and hepatocytes (26, 29, 30). Here, JUN is linked to soft tissue sarcoma.