CARM1 is an H3 R17 methyltransferase that is recruited to the TFF promoter where, in conjunction with acetyltransferases, it establishes transcriptionally active chromatin (Métivier et al, 2003; Chen et al, 2000; Daujat et al, 2002). PRMT1 is an alternate arginine methyltransferase with activity toward H4 R3 that acts at the TFF enhancer, however CARM1 and PRMT1 are never found simultaneously at the TFF1 gene (Métivier et al, 2003; reviewed in Xu et al, 2003; Arnal et al, 2017).Note that in this diagram, methylation of H3 R17 is not depicted.