1 INTRODUCTION Twist1, an evolutionary highly conservative transcription factor with a basic helix–loop–helix (bHLH) domain, is composed of a basic amino acid, a variable-length loop, and amphipathic α-helixes.1, 2 Each of the α-helices of Twist1 may couple with other bHLH molecules to form homo- or heterodimers, which then bind to a canonical hexanucleotide sequence (CANNTG) known as E-box motif, leading to activation or repression of the transcription of its target genes.1, 3-5 It is...
