Although the bone defects observed in severe laminopathies such as HGPS could be also associated with accumulation of prelamin A in the presence of normal lamin C expression [19], for the purposes of this study we tested the role of the inner nuclear protein MAN-1 as one of the potential explanations for the limited capacity of the Runx2 complex to bind the nucleus and initiate osteogenic transcription in the absence of lamin A/C. Here, RUNX2 is linked to Hutchinson-Gilford progeria syndrome.