CYLD and neoplasm: To further reinforce our findings showing the role of CYLD as a protector from aging and tumor development, we analyzed the phenotype of the transgenic mice in a different genetic background (i.e., FVB/N background) and found that K5-CYLDC/S /FVB/N mice develop similar alterations to those described above, i.e., they showed premature aging of skin and other organs (thymus, pancreas, stomach, lung etc.)(Fig. S10 and S11) and develop spontaneous tumors (from 8-10 months onwards), while their age-matched Control littermates do not show tumor development (Fig. S12).