SMAD2 and prostate cancer: The PI3K/Akt signaling pathway was reported to be the key pathway causing phenotype changes in associated cells to a more proinflammatory state [36], and it could interact with MMP expression in various kinds of cells, including LoVo cells [37], prostate cancer cells [38], etc. It might be worth studying the involvement of the Smad2/3, MEK-ERK1/2, and PI3K/Akt signaling pathways in the DDR1-mediated regulation of MMPs.