The study investigates the intercellular transfer of cancer cell invasiveness via endosome-mediated protease shedding. Overexpression of MT1-MMP, a matrix metalloproteinase, promotes cancer cell invasion by transferring its catalytic ectodomain to non-invasive cells. This transfer depends on the presence of TKS4 and TKS5, adaptor proteins involved in invadopodia formation. In acidic endosomes, TKS4/5 promote ADAM-mediated cleavage of MT1-MMP by bridging the two proteases. The cleaved ectodomain is then secreted into extracellular vesicles (EVs) and transferred to recipient cells, converting them into invasive phenotypes. The PX domains of TKS4/5 interact with the cytosolic tail of MT1-MMP and endosomal phosphatidylinositol 3-phosphate, facilitating the process. Overexpression of TKS4/5 and MT1-MMP enhances intercellular transfer of cancer cell invasiveness. The study provides insights into the mechanisms by which MT1-MMP and TKS4/5 promote cancer progression and metastasis.The study investigates the intercellular transfer of cancer cell invasiveness via endosome-mediated protease shedding. Overexpression of MT1-MMP, a matrix metalloproteinase, promotes cancer cell invasion by transferring its catalytic ectodomain to non-invasive cells. This transfer depends on the presence of TKS4 and TKS5, adaptor proteins involved in invadopodia formation. In acidic endosomes, TKS4/5 promote ADAM-mediated cleavage of MT1-MMP by bridging the two proteases. The cleaved ectodomain is then secreted into extracellular vesicles (EVs) and transferred to recipient cells, converting them into invasive phenotypes. The PX domains of TKS4/5 interact with the cytosolic tail of MT1-MMP and endosomal phosphatidylinositol 3-phosphate, facilitating the process. Overexpression of TKS4/5 and MT1-MMP enhances intercellular transfer of cancer cell invasiveness. The study provides insights into the mechanisms by which MT1-MMP and TKS4/5 promote cancer progression and metastasis.