The development of a typical RA-like phenotype was achieved following murine treatment with K/BxN serum [16] (Fig.4), and a TET3 gene-depleted CL57BL/6 line was used as no overt abnormality with normal reproductive ability has been observed in mice with TET3 haploinsufficiency [17, 18]. The gene discussed is TET3; the disease is rheumatoid arthritis.