TGFB1 and periodontitis: A recent study by Chang et al. (2019) measured the amount of certain growth factors (i.e., EGF, IGF‐1, PDGF‐BB, TGF‐β1, and VEGF) from PRF membranes and exudates from healthy and periodontitis subjects and found no significant differences between the groups (all p > 0.05).