MMP12 and breast cancer: Interestingly, whilst MMP12 expression was largely absent in the PDX human component (mean log2 FPKM = 0.44) and cell lines of the Cancer Cell Line Encyclopaedia [18] (CCLE; mean log2 signal = 4.51) representing pure tumor cell populations (Figure 3A), significant over-expression in BTNBC was detected in clinical samples from The Cancer Genome Atlas [19] (TCGA; log2FC = 2.89, FDR = 2.67E–14) and the Utah Breast Cancer Study (UBCS; log2FC = 2.56, FDR = 1.21E–02; Figure 3B).