IHC staining for myogenic regulatory factors MYOD1 and MYOGENIN revealed diffuse, homogenous staining in all TCP tumors while the MCP tumors had focal, distinct areas of staining scattered throughout the tumor that were more consistent with tumors with mesenchymal and epithelial differentiation than with ARMS (Supplementary Fig. 4d). This evidence concerns the gene MYOD1 and neoplasm.