Immunodeficiency Immune deficiency UMLS:C0021051 Failure of the immune system to protect the body adequately from infection, due to the absence or insufficiency of some component process or substance. HP:0002721 Decreased immune function SNOMEDCT_US:234532001 MSH:D007153 HP:0005371 HP:0005362 human_phenotype Abnormality of immune system physiology