Exosomal miR-301a secreted by hypoxic pancreatic cancer cells mediates M2 macrophage polarization via the activation of PTEN/PI3Kγ pathway to accelerate tumor metastasis [15], and hypoxic tumor-derived exo-miR-135a-5p initiates favorable pre-metastatic niche formation to promote liver metastasis of colorectal cancer [16]. The gene discussed is PTEN; the disease is neoplasm.