SOX9 and cancer: Our results revealed that SOX9‐TCF7L2 double‐high cancer cells exhibited significantly higher level of P21 compared to SOX9‐TCF7L2 double‐low cells (Figure S9B–D, Supporting Information), supporting a P21‐mediated G1/S cell cycle arrest in SOX9/TCF7L2 double‐high GBC cells.