The Nf1flox/−;Col2.3Cre+ mouse model that closely recapitulates the skeletal abnormalities found in the human NF1 disease has hyperactive TGF-β1 signaling.413 The exact mechanisms underlying mutant neurofibromin-associated hyperactivation of TGF-β signaling remain unknown, particularly in relation to the osseous defects. This evidence concerns the gene TGFB1 and neurofibromatosis type 1.