Dephosphorylation can play a key role in molecular biology, particularly cloning using restriction enzymes. The cut ends of a vector may re-ligate during a ligation step due to phosphorylation. By using a desphosphorylating phosphatase, re-ligation can be avoided. Alkaline phosphatases, which remove the phosphate group present at the 5′ terminus of a DNA molecule, are often sourced naturally, most commonly from calf intestine, and are abbreviated as CIP.