Type 1 and type 2: a fundamental dichotomy for all T-cell subsets.

@article{Carter1996Type1A,
  title={Type 1 and type 2: a fundamental dichotomy for all T-cell subsets.},
  author={Laura L. Carter and Richard W. Dutton},
  journal={Current opinion in immunology},
  year={1996},
  volume={8 3},
  pages={336-42}
}
Cytokine secretion is not confined to CD4+ T cells; rather, Type 1 and Type 2 populations of CD8+ and gamma delta T cells can also be generated in vitro and isolated from in vivo situations. These subsets and their physiological functions are significant.