All of the following are functions of CD4 helper cells except:

Immunoglobulins are secreted from the B lymphocytes. however, T helper cells helps the B cells, by activating it and produce into plasma cells. These plasma cells secrete the immunoglobulins. Thus, T helper cells indirectly helps in secretion of immunoglobulins. Ref: Andrew E. Williams, "The immune system", In the book, "Immunology: Mucosal and Body Surface Defences", USA, Wiley Blackwell Publications, Chapter 1.13; Medical Microbiology By Jawetz , 24th Edition, Page 140; Medical Microbiology By Muray, 6th Edition, Pages 119-20; Review of Microbiology and Immunology, 9th Edition, Page 405