Typically, the M1 type is thought to inhibit tumor growth, while M2 polarization has a supportive role to promote tumor progression.32 To look into how BMDMs are affected by the exosomal Rab22a-NeoF1 fusion protein during lung metastasis, we hypothesized that the exosomal Rab22a-NeoF1 fusion protein may affect macrophage polarization. This evidence concerns the gene RAB22A and neoplasm.