MMP7 and posterior cortical atrophy: BE and LE signature feature plots also revealed a cluster of cells (cluster 5) that we termed other epithelial (OE) cells (Fig. 2a, c) with lower BE and LE signatures scores (Supplementary Fig. 1a) and were characterized by several markers previously identified as associated with PCa including PIGR, MMP7 and CP (Fig. 2b).