Additionally, SIMON uncovered previously unappreciated immune subsets with an important role in influenza immunity, specifically cytotoxic CD8+ T cells (subsets having effector, effector-memory and/or Tc17 phenotype) and CD161-expressing CD4+ T cells in mediating protective immunity, revealing that influenza immunity is far more complex than previously thought [59]. Here, KLRB1 is linked to influenza.