Then H&E staining results displayed that in the control group, thyroid tumor cells of nude mice had normal and clear outlines, abundant cytoplasm, obvious nucleoli and heterotypy; in the PKM2-silenced group, thyroid tumor cells were seen to have necrotic cells, increased nuclei division and blurred cell outlines; the number of necrotic thyroid cells in the PKM2-silenced group was reduced compared with that in the control group (Fig. 5C). The gene discussed is PKM; the disease is thyroid tumor.