What Leukocyte alkaline phosphatase (LAP Score)

 Is also known as neutrophil alkaline phosphatase because only neutrophils are the only leukocyte that normally contains various alkaline phosphatase  To differentiate Chronic myelocytic leukemia (CML) from leukemoid reactions or other myeloproliferative disorders (PV, ET, PMF)  The CML has a decrease Lap score compared to the Leukemoid reactions.