We first measured the expression of IGF2BPs in WT and Fas KO CD8+ T cells isolated from recipient mice 5 days after infection in the in vivo co-transfer model by qPCR, and found that IGF2BP3, but not IGF2BP1 and IGF2BP2, had enhanced expression in KO cells, suggesting it might play a regulatory role in FTO ablated CD8+ T cells (Supplementary Fig. 7B). Here, FTO is linked to infection.