MMP13 and breast cancer: To expand on our RNA-seq analysis and confirm the role of CRP2 in regulating pro-invasive MMP expression in breast cancer cells, we knocked down CRP2 in MDA-MB-231 cells using two different siRNAs (Figure 2A) and assessed the expression of several MMPs associated with breast cancer progression, namely, MMP-2, MMP-9, MMP-13, MMP-14, MMP-15 and MMP-16, using real-time quantitative reverse transcription PCR (RT-qPCR).