TERC and neoplasm: The explanation offered by the authors for the promotion of tumor development In these independent models invoked the ability of telomerase in the K5TRF2 telomerase proficient model to provide for continuous cell division, whereas a “DNA damage response (DDR) induced by short telomeres” would be responsible for tumorigenesis in the telomerase-deficient K5TRF2/Terc−/− mice.