Deoxycytidine kinase (dCK) is a crucial enzyme in the nucleotide salvage pathway, facilitating the phosphorylation of deoxycytidine, deoxyadenosine, and deoxyguanosine to their respective monophosphates. This process is vital for DNA synthesis and repair, making dCK a significant target in cancer therapy, especially in the activation of nucleoside analog prodrugs.