A recent study reported that amplification and overexpression of E2F3 resulted in oncogenic activity in human bladder cancer development.26 E2F3 expression can be regulated by binding of promoter regions in target genes.27 We therefore performed immunohistochemistry and immunofluorescence analyses and found that QKI‐6 expression was inversely associated with E2F3 expression in bladder cancer tissue specimens (Figure 7A,B), whereas E2F3 expression was inversely associated the QKI‐6 mRNA and protein expression (Figure 7, 8, 9, 10C‐F). This evidence concerns the gene E2F3 and urinary bladder cancer.