Since PGE2 may enhance the IL-1β-induced MMP-1 expression,6 a decrease in the production of PGE2 by keloid-derived fibroblasts may have implications in the decreased production of MMP-1 by keloid fibroblasts, which may contribute to the accumulation of extracellular matrix as seen in the keloid tissue. This evidence concerns the gene MMP1 and keloid.