In addition to collagen-degrading enzymes, we examined the gene-expression levels of collagen-cross-linking enzymes, such as LOX, LOXL-1, LOXL-2 and LOXL-3, finding that they were substantially upregulated in keloid dermal fibroblasts relative to either normal or hypertrophic dermal fibroblasts (Figure 3b). This evidence concerns the gene LOXL1 and keloid.