Pathology An important step in activation of naive CD4 +T cells and initiation of cell-mediated immune response is played by Interleukin- A 2 B 1 C 3 D 4 💡 Explanation An important step in activation of naive CD4 +T cells and initiation of cell-mediated immune response is played by Interleukin- ✓ Correct Answer: A. 2