On the other hand, Bayat and colleagues found that plasma TGF-beta1 levels did not vary significantly between Caucasian patients with keloids, hypertrophic scars and controls and that polymorphisms in TGFB1, TGFB2, and TGFBR1 were not associated with keloids or hypertrophic scars [11-13]. Here, TGFB1 is linked to keloid.