MYT1 also known as PKMTY1 is a member of the serine/threonine protein kinase family. MYT1 plays a crucial role in cell cycle regulation, specifically in the phosphorylation of Cdc2, a key protein that controls the transition from G2 phase to mitosis. MYT1 phosphorylates Cdc2 on threonine 14 and tyrosine 15, which is essential for keeping Cdc2 in an inactive state during S and G2 phases of the cell cycle. This regulation is vital for ensuring proper cell division and preventing premature mitotic entry, which could lead to genomic instability. MYT1 activity is tightly controlled throughout the cell cycle, and MYT1 interaction with other proteins, such as Wee 1 kinase, highlights MYT1′s importance in the mitotic control network. Dephosphorylation of Cdc2 by Cdc25 in late G2 phase activates the Cdc2/cyclin B complex, allowing cells to progress into mitosis.