TBX21 and neoplasm: However, a very common pattern among ChromVAR-implicated TFs was high initial expression in memory cells at the PreCAR timepoint, followed by a convergence in expression between memory and naïve-derived CAR T cells at the PostCAR and Tumor timepoints, as seen with bZIP family members Jun, Fos and Atf3, along with the gene Tbx21, encoding canonical effector TF T-bet (Figure 5D).