ECM1 and cancer: Because ECM1 is a secreted protein, to assess the effect of ECM1 on the tumor microenvironment, we first detected the secreted ECM1 in CMs of different cancer cells, and found that ECM1 was highly secreted in A8, Hey, and A2780-ECM1 cells compared with in ECM1 knockdown and A2780 cells (Figure 4A and Figure S3A).