You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Type I helper cells secrete: and explain in detail?
IL -2 
• Interleukins are “cytokines”.
• Proteins of usually low molecular weight.
• Regulating important biological processes.
• Interleukins are produced by Monocytes, Macrophages, B and T Lymphocytes, mast cells, neutrophils. 
IL1 causes fever
IL2 T cell stimulation
IL3 Bone Marrow stimulation
IL4 IgE Stimulation
IL5 IgA Stimulation