TCF7 and infection: Upon transducing in vivo primed SMARTA CD4+ T cells with TCF-1 (full-length CDS of P45 isoform without 3′ untranslated region39) retrovirus (Fig. 7a), on day 8 post LCMV-Armstrong infection, we observed a significant increase in TCF-1 expression in METTL3-deficient SMARTA cells (Fig. 7b).