Furthermore, MMP3, a matrix metalloproteinase involved in collagen remodeling [52] and PTX3, a gene involved in innate immune responses that is found to be elevated in the serum of SSc patients and that is constitutively expressed in SSc fibroblasts [53], [54] were downregulated in SSc fibroblasts following inhibition of PKC-δ activity (Figure 7). The gene discussed is MMP3; the disease is systemic sclerosis.