Exosomal miR-301a-3p secreted from ESCC cells causes M2 macrophage polarization via the inhibition of PTEN expression and activation of the PI3K /AKT signaling pathway and then promotes angiogenesis via the secretion of the angiogenic factors VEGFA and MMP9. The gene discussed is AKT1; the disease is esophageal squamous cell carcinoma.