TCOF1 and Treacher-Collins syndrome: However, herein the use of TRA-MO generated a milder condition, probably because the splicing MO also generated RNAs encoding Treacle dominant-negative isoforms.14 This mild condition may explain the absence of significant differences not only in the relative abundance of cnbp transcripts but also in the expression of its targets, tbx2b and tcf7l2. 23, 36 Nevertheless, the strong statistical correlation between CNBP and TCOF1 expression in human mesenchymal cells further supports the hypothesis of a functional link between these two genes in the pathology of TCS.