Final answer:
Calcineurin helps activate interleukin-2, which is key for the growth and differentiation of T cells and is a critical component of the adaptive immune response.
Step-by-step explanation:
Calcineurin is an essential protein in the activation of interleukin-2 (IL-2), which promotes the growth and differentiation of T cells.
Interleukins are a class of cytokine signaling molecules that play various roles in the immune system, including the differentiation and maturation of cells which contribute to producing immunity and inflammation. Helper T cells, or Th cells, secrete cytokines to enhance immune responses and are essential in the activation of both B and T cell lymphocytes. Specifically, IL-2 is a key cytokine involved in T cell proliferation, and it's part of the adaptive immune response.