Immunofluorescence analysis of mouse tumours demonstrated that the number of MELK‐, Ki‐67‐ and CDK2‐positive cells was lower in the MELK inhibition group than it was in the control group, while the number of cells with p‐ATM‐, p53‐ and p21‐positive staining was higher. The gene discussed is ATM; the disease is neoplasm.