To verify the cell cycle arrest at G1 phase in SOX9/TCF7L2 double‐high cells identified by single‐cell transcriptomic analysis, we utilized multiplex immunohistochemistry (mIHC) to evaluate the protein level of P21, a well‐established marker of G1/S cell cycle arrest,[50] in a representative gallbladder cancer tissue sample (Figure S9A, Supporting Information). Here, SOX9 is linked to gallbladder cancer.