Given that miR-629-3p is expressed at considerably higher levels in TNBC cells than in luminal breast cancer cells, we hypothesized that the signaling pathways promoting lung metastasis are partially shared by the two different breast cancer subtypes, in which the miR-629-3p/LIFR axis plays an important role regardless of ER expression, which requires further study. Here, ESR1 is linked to breast carcinoma.