MMP7 and breast cancer: C-c motif chemokine ligand 27 (CCL27), a chemokine primarily expressed by keratinocytes, and its enhanced expression activate the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway and in turn overexpress MMP-7 leads to cell invasion and migration of breast cancers (Korbecki et al., 2020).