A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.

Synonyms: CD4 Positive T Lymphocytes, T4 Cell, CD4-Positive T-Lymphocyte, CD4-Positive Lymphocytes, CD4-Positive Lymphocyte, T4 Lymphocytes, T4 Cells, Lymphocytes, CD4-Positive, T4 Lymphocyte, T-Lymphocyte, CD4-Positive, Lymphocyte, CD4-Positive, T-Lymphocytes, CD4-Positive, CD4-Positive T-Lymphocytes