Statistically, the PDE4D expression was found to be significantly lower in the bladder tumor tissues than that in adjacent normal bladder tissues (P = 0.009) (Fig. 5a-c, Additional file 9: Figure S9, Additional file 10: Table S1), and the low PDE4D expression was positively correlated to the poor prognosis (Fig. 5d). This evidence concerns the gene PDE4D and urinary bladder neoplasm.