Proteolytic activity of estrogen positive breast cancer cells treated with extracellular CYR61 was increased (Figure 1F; MCF-7 rhCYR61: 110.8 ± 2.65 SEM relative proteolytic activity in % compared to MCF-7 control; n = 3; P = 0.015; T47D rhCYR61: 106.2 ± 1.806 SEM relative proteolytic activity compared to T47D control; n = 3; P = 0.026), while proliferation was not altered (Figure 1, Figure S2C). Here, CCN1 is linked to breast cancer.