The subject matter disclosed herein is generally directed to novel CD8+ tumor infiltrating lymphocyte (TIL) subtypes associated with response to immunotherapy treatment. Specifically, the subtypes are associated with checkpoint blockade therapy. Moreover, the subject matter disclosed herein is generally directed to methods and compositions for use of the subtypes. Also, disclosed herein are gene signatures and markers associated with the subtypes and use of said signatures and markers. Further disclosed are therapeutic methods of using said gene signatures and immune cell subtypes. Further disclosed are pharmaceutical compositions comprising populations of CD8+ TILs enriched for a specific subtype.