scRNA-seq of spleen CD8+ TM cells isolated day 7 after LCMVc13 infection showed that anti-apoptotic genes such as Bcl2, Mcl1 and Xiap were diminished, while pro-apoptotic genes like Bax and Bid35,36 were elevated in GFI1ΔCD8 CD8+ T cells compared to WT CD8+ T cells (Extended Data Fig. 9e). Here, MCL1 is linked to infection.