GZMB and viral infectious disease: Out of the seven distinct clusters, three matched established subsets: a population of naïve T cells overexpressing Lef1, Sell, and Igfbp4 genes (referred to as ‘Naïve’); a population of Tregs, identified by their classical expression of the Foxp3 gene, along with the expression of naïve-associated genes Lef1 and Sell [18]; and cells overexpressing genes such as Eomes and Gzmb, which are commonly associated with CD8 T cells (denoted ‘Cytotoxic’) and have been previously described as CD4 cytotoxic T cells in the context of viral infection and cancer [19].