TGFB1 and keloid: Contrary to the general expectation that cryotherapy reduces the migration or proliferation ability of keloid fibroblasts through the inhibition of collagen synthesis [17], molecular analysis revealed that the proliferation and migration abilities of keloid fibroblasts from the deep tissue were significantly enhanced after cryotherapy, possibly due to the overexpression of MMP9 and activation of TGF-β signalling pathway.