Question: Our provider does testing for antibodies to HLA in a patient to confirm the genetic structure of his cancer and determine response to treatment. Can we report for the HLA testing? This seems like a laboratory test. Florida Subscriber Answer: Human leukocyte antigen (HLA) testing is a laboratory test, and therefore only the lab performing the service should report the code. Understanding the codes may be of use to your oncologist when he orders the tests. The lab chooses from the following codes for antibodies to HLA depending upon whether your physician orders testing for HLA Class I, HLA Class II, or both.