For example, G1/S-phases are associated with delayed Erk activation and G2 with rapid sustained signaling in yeast,52 whereas mESCs display spontaneous pulses of Erk activity early in the cell cycle.49 Although the mechanism of mitotic erasure is currently unknown, the Cdc25 dual-specificity phosphatases are attractive putative regulators as they are active in late G2 phase to induce Cdk1 activity.53 Although it is currently unknown whether they dephosphorylate P-Erk targets, Cdc25A can function as an ERK phosphatase in human hepatoma cells.54,55. Here, CDK1 is linked to hepatocellular carcinoma.