To investigate the relationship between TOP2A and RRM1 expression and cancer recurrence after treatment with pirarubicin or gemcitabine, in total, among 45 patients who underwent intravesical chemotherapy with pirarubicin, 32 had tumours that positively expressed TOP2A and 13 had tumours that negatively expressed TOP2A (Figure 1E). This evidence concerns the gene RRM1 and cancer.