SOX9 and neoplasm: This study utilized scRNA‐seq and ST‐seq to elucidate the pivotal role of the SOX9/TIMP1 axis in immune evasion in GC and confirmed the mechanism by which iRGD NPs@si‐SOX9/CL enhance DC function and promote anti‐tumor immune responses during PDT by inhibiting the SOX9/TIMP1/FAK/PI3K signaling axis (Graphical abstract).