The downstream target genes upregulated in aged MTC to Crlf1/Lifr pair functioned in inflammatory response (Abl1, Elmo1, Tpm1, Aldoa, Bhlhe40, Cirbp, Elf3, Smad7), cell cycle arrest (Btg2, Cdkn1a, Dusp1), cellular senescence (Cpeb4, Ier2), maintenance of stem cell quiescence (Hes1), cell death (Slc2a1, Zfp36, Dusp1), and innate immunity (Hk1, Irf9, Pim1) (Figure 4f). This evidence concerns the gene BTG2 and medullary thyroid gland carcinoma.