TERF1 and lung carcinoma: Finally, to address the in vivo role of these TRF1 modifications by AKT1, we transduced eGFP-tagged Trf1 wild-type and mutant alleles in both primary p53-deficient MEFs (Trf1T248A, Trf1T330A, Trf1S344A, Trf1T330A/S344A, and Trf1T248A/T330A/S344A mutants) and in CHA 9-3 lung cancer cells (Trf1T330A, Trf1S344A, and Trf1T330A/S344A mutants) (Fig. 6a).