MMP3 and nasal cavity polyp: Regarding the correlations of ECM proteins with the expression of MMPs and TIMPs, and the fact that fibroblasts are the main source of MMPs and TIMPs, we first observed the regulation by ECM proteins of MMP‐3, MMP‐7, MMP‐8, MMP‐9 and TIMP‐1, and TIMP‐2 gene expression in nasal polyp‐derived fibroblasts.