Based on previous lncRNAs’ function and BC ET mechanism, we speculate that LINC00309 enhanced ET resistance through the direct influence on the up- or down-regulation of ER transcript-related gene expression function, which promotes BC cell growth and proliferation, or its influence on PI3K/AKT, mTOR, or NF-κB signal pathways. The gene discussed is MTOR; the disease is essential thrombocythemia.