To clarify which RBP was responsible for the interaction, we silenced YBX2-A, PUM2 and EIF4B in RBE cells (Fig. S11A, 11B) and detected that only EIF4B knockdown decreased miR-30a-5p level in CCA-derived exosomes, implying EIF4B facilitated the loading of miR-30a-5p into exosomes (Fig. 6C). The gene discussed is PUM2; the disease is cholangiocarcinoma.