Haematoxylin and eosin staining were performed as previously described (Maharani et al., 2018 (link)). Immunohistochemistry analysis was performed as previously described (Gulay et al., 2021 (link)) with slight modifications, as described below. Heat‐induced antigen retrieval was performed twice in Tris‐EDTA buffer (pH 9.0) in a microwave oven for 5 min. Tissues were stained with mouse anti‐Ki‐67 monoclonal antibody (Clone MIB‐1, DAKO) and mouse anti‐5mc monoclonal antibody (33D3, Abcam) overnight at 4°C. To measure the Ki‐67 labelling index, more than 1000 cells were counted in randomly selected high‐power fields, and the number of Ki‐67‐positive nuclei was recorded in each field. The labelling index was defined as the ratio of Ki‐67‐labelled cells to the total number of cells counted and was expressed as a percentage. 5mc values were calculated from OD mean value from >1000 cells in each patient analysed by QuPath ver. 0.2.1 (Bankhead et al., 2017 (link)).