Given the upregulation of CDC42-v2 in PTBP1-knockdown tumor cells, which were showed in our previous study to have inhibited cell growth and impaired transformation properties [8], and decreased expression of this variant in a panel of ovarian cancer cell lines and ovarian tumor tissues (Figures 6A and 6B), we wondered whether CDC42-v2 had any antitumor activity and could mediate the antitumor effects of PTBP1 knockdown on tumor cells. The gene discussed is PTBP1; the disease is ovarian cancer.