TGFB1 and cancer: Furthermore, KEGG pathway analysis revealed that the ratios of cytokines between A/sEVs and S/sEVs apparently activate multiple oncogenic pathways, such as TGF‐β, Toll, Jak‐STAT, and MARK, which consequently promote metastasis of several types of cancer through enhancement of EMT and immune evasion (Fig. 2D and Fig. S2A–E).