PNK1 also known as PNK, PNKP is a member of the DNA 3′ phosphatase family. PNK1 plays a crucial role in DNA repair mechanisms, particularly in response to damage from radiation or oxidative stress. PNK1 encoded by the PNKP gene, features a 3′-phosphatase domain that shares similarities with L-2-haloacid dehalogenases and possesses an ATP binding site, which is essential for enzymatic activity. PNK1 is predominantly located in the nucleus, where PNK1 catalyzes the phosphorylation of DNA at hydroxy termini while also having the ability to dephosphorylate 3′-phosphate termini. PNK1 expression is notably high in tissues such as the testis, pancreas, spleen, kidney, and heart, highlighting its importance in cellular processes related to DNA integrity and repair.