To establish whether Nell-1 blockade will inhibit Runx2-mediated osteogenic differentiation, wild-type NMCCs were pretransfected with Nell-1 siRNA (siRNANell-1) or unrelated negative control siRNA 24 hours prior to AdRunx2 infection and compared with AdRunx2 transduction alone and no treatment controls (Fig. 5A, B). The gene discussed is NELL1; the disease is infection.