Exosomal miR-519a-3p triggers the activation of the MAPK/ERK pathway by targeting dual specificity phosphatase 2 (DUSP2), resulting in the M2-like polarization of macrophages, facilitating the establishment of a pre-metastatic intrahepatic niche, and promoting GC-LM progression (53). The gene discussed is DUSP2; the disease is lymphangioma.