A non-functional Gemc1Δ4-5 mutant transcript was detectable in the CP of the Lcre;p53cko;Rbcko;Gmnccko mice, but its presence was dramatically reduced in tumor cells in these animals, indicating similar impairment in the upstream regulation of Gmnc (Fig. 3B, D). The gene discussed is GMNC; the disease is neoplasm.