Both the frequency of Sca-1 positivity, which characterizes the stem phenotype, and of PCNA positivity, which marks proliferation, were substantially (p < 0.01) reduced in IL-30-silenced tumors when compared with controls, regardless of whether the tumor hosts were WT or IL-30KO (Table 1 and Additional file 2: Figure S1). The gene discussed is IL27; the disease is neoplasm.