We found that all cases involved in the test with longitudinal blood collections showed a significant decrease in TβRII+ crEVs levels after surgical resection (average from 63.06% to 22.05%; average from 1.66 ng/ml to 0.47 ng/ml) and a significant increase of TβRII+ crEVs levels in relapsed breast cancer patients (average from 22.05% to 43.45%; average from 0.47 ng/ml to 1.33 ng/ml) (Fig. 2g, h). Here, TGFBR2 is linked to breast cancer.