QSOX2 and neoplasm: IGF‐1 is mainly secreted by CAFs (Figure 6D) and has been reported to activate Akt/mTOR signaling to promote tumor progression.[26] To confirm whether IGF‐1 upregulates QSOX2 expression, we treated KYSE180 cells with graded concentrations of IGF‐1 recombinant protein for 24 h.