The group reported that exosomes mediate the RN7SL1 transfer from stromal cells to breast cancer cells: 5‐ethynyl uridine‐modification by azide‐linked fluorescein allowed to see the horizontal acquisition of stromal cell RNA, represented by transcripts regulated by POL3 besides RN7SL1 (White, 2011). Here, RN7SL1 is linked to breast carcinoma.