For example, TCR Vβ usage has been studied on CD3+, CD4+, and CD8+ T cells [74,88,89] in LGL leukemia patients, or in naïve, effector, and memory lymphocytes in healthy subjects [57], or in total CD4+ and CD8+, effector CD4+CD28+ and CD8+CD28+, and effector memory CD4+CD28−CD57+ and CD8+CD28−CD57+ cells in AA [53,70,71]. The gene discussed is CD28; the disease is T-cell large granular lymphocyte leukemia.