ANGPT2 and hepatocellular carcinoma: To confirm the release of exosomal ANGPT2 from recipient HUVECs, HUVECs were cultured with fresh medium after coculture with ANGPT2-mCherry-expressing exosomes derived from HCC cells for 6 h and the wash with phosphate-buffered saline (PBS), immunoblotting showed that HCC cell-secreted exosomal ANGPT2 was positive in HUVEC-cultured medium and HUVEC-derived exosomes (Additional file 5: Figure S2B; Fig. 3d).