Tudor domains are small protein structural motifs of about ~50 amino acids related to the “royal family” of methyl readers, which also includes chromo, MBT, PWWP, and Agenet-like domains. Tudor domains occur either alone, in tandem, or with other domains and are found in many proteins that are involved in RNA metabolism, germ cell development, transposon silencing, DNA damage response, histone modification, and chromatin remodeling. The tudor domains recognize symmetric methylated arginine or methylated lysine residues. JMJD6 is a 403 amino acid nuclear protein lysyl-hydroxylase that has been reported to have arginine demethylase activity for histone H3 at ‘Arg-2’ and histone H4 at ‘Arg-3’. JMJD6 has been sμggested to function in the differentiation of multiple organs during embryogenesis and regulate hematopoietic differentiation and macrophage cytokine responses. First identified as a putative phosphatidylserine receptor involved in phagocytosis of apoptotic cells, JMJD6 was later indicated not to directly function in the clearance of apoptotic cells. It is ubiquitously expressed in most tissues and is upregulated in patients with chronic pancreatitis and upon cytokine treatment, but not upon TNF-α treatment.