https://www.ncbi.nlm.nih.gov/pmc/articles/PMC220898/?page=3 Day 227 has 47 protein-coding genes (browser view) including 9 MMP genes (matrix metalloproteinase).
MMPs, or matrixins, are enzymes that break down the extracellular matrix. These important proteins were first discovered in 1962 when a tadpole fin was shown to break down a collagen plate.
Click here to see all 8442914 letters of Day 227 with MMP1 underlined.