MAFB and Duane retraction syndrome: MAFB consists of two parts: the N-terminal transactivation domain, which is involved in MCTO disorder, and the C-terminal DNA-binding domain, including the leucine zipper required for dimerization and responsible of Duane retraction syndrome (DURS3; OMIM#617041) consisting in congenital ophthalmologic complications for the restriction of horizontal eye movements and eyeball retraction upon adduction with or without inner-ear defects [20].