While Ninel Azoitei et al. reported PKD2 siRNA lead to an accumulation of glioblastoma cells in G1 phase by a down-regulation of cyclin D1 expression38, we found that lower PKD2 induced A549 cells arrest in G2/M phase, which was consistent with the reports that PKD2 modulated cell cycle by stabilizing Aurora A kinase at centrosomes39. The gene discussed is CCND1; the disease is glioblastoma.