2007) (Figure S4A,B) highlighting that IFN and inflammatory phenotypes in the tumour microenvironment may trigger tetherin expression with a predicted impact on regulating the balance of exosome release and retention. Additionally, it is possible that tetherin influences ECM degradation and breast cancer cell migration through mechanisms beyond MT1‐MMP and exosome tethering. For example, tetherin can interact with the transcription factor NF‐κB (Tokarev et al. 2013) which in turn regulates the expression of several MMPs (Bond et al. 2001) and invadopodia formation (Hu et al. 2022). Here, IFNA1 is linked to breast cancer.