In contrast to these findings, it was shown that genetic and pharmacological inhibition of PDE5 activity strongly enhanced cell motility and invasiveness in human glioblastoma T98G cells, whereas PDE5 overexpression in PDE5-negative U87G cells significantly inhibited their invasive potential and interfered with DNA damage repair and cell survival following irradiation [253]. Here, PDE5A is linked to glioblastoma.