DIO1 and hypothyroidism: While both DIO1 and FOXE1 were previously associated with FT4 levels and hypothyroidism by candidate gene analysis and functional studies [17]–[19], [38]–[41], association at LHX3 is novel and is consistent with the essential role of this transcription factor in pituitary development (see above) [30], [31], [42], [43].