The above data suggest that variations in protein accumulation in the cytoplasm, DNA binding, transactivation activity of RUNX2 at its target genes, or heterodimerization with CBFβ lead to altered transcription activities and variable degrees of haploinsufficiency or protein activity [19], having an important role in the variable clinical expression of CCD [15]. Here, CBFB is linked to cleidocranial dysplasia 1.