Osteoinduction from allograft (demineralized bone matrix) involves all of the following growth factors EXCEPT one. Which is the EXCEPTION?

Correct answer: A. Interleukin-1 beta (IL-1β)

• A. CORRECT — IL-1β is NOT an osteoinductive growth factor. It is a pro-inflammatory cytokine primarily involved in bone resorption and inflammation, not in triggering differentiation of progenitor cells into osteoblasts. It is not a component of the osteoinductive cascade from allograft.
• B. TGF-β is present in bone matrix and potentiates BMP-induced osteogenesis. It coordinates bone resorption and formation, stimulates osteoblast proliferation, and plays a major role in bone regeneration and remodeling.
• C. PDGF is found in DBM and contributes to bone regeneration by stimulating cellular recruitment, angiogenesis, and matrix remodeling. It is considered part of the growth factor milieu that supports bone healing from allograft, though its role in direct osteoinduction is more modulatory than primary.
• D. BMP is the primary driver of osteoinduction. Demineralization of bone matrix exposes BMPs, which stimulate progenitor cells to differentiate into osteoblasts. BMPs are central to why DBM has osteoinductive properties.