CDK1 and amyotrophic lateral sclerosis: In the present study, we found a significant increase in the level of p-CDC25C (Ser216), total cyclinB1, and p-CDC2 (Tyr 15), but a decline in the level of PLK1, p-cyclinB1 (Ser133), suggesting that the PLK1-CDC25C-cyclinB1 and CDC2 complex axis is involved in ALS-induced G2/M cell cycle arrest in Caco-2 cells.