Monocytes from COVID-19 patients expressed increased levels of various collagen subunits (COL1A1, PLOD2, COL6A3, COL6A1), enzymes involved in collagen triple helix synthesis (COLGALT1) and a number of matrix metalloproteinases (MMP1, MMP2, MMP14, Fig. 5d), which are not only involved in extracellular matrix remodeling, but they have also been implicated in contributing directly to platelet activation and priming for aggregation39,40. Here, MMP2 is linked to COVID-19.