Helper T cell

These are a type of T-cell lymphocyte that express CD4 and do not have cytotoxic or phagocytic capabilities. Increased numbers of CD4+ T-cells could be due to a maligancy such as T-cell lymphoma (neoplastic T-cells) or Hodgkin lymphoma (non-neoplastic background T-cells), certain infections such as Mycobacterium tuberculosis or fungi with granulomatous inflammation (granuloma).