SNU‐398 cells with DUSP9 overexpression (SNU‐398‐oe.DUSP9) exhibited enhanced tumour growth compared to vector control cells (SNU‐398‐oe.VEC), as evidenced by faster tumour onset and increased tumour volume, though both groups formed tumours across all inoculation doses (5 × 105, 5 × 104 and 5 × 103 cells; Figure 6A–D,I). The gene discussed is DUSP9; the disease is neoplasm.