EGF and cancer: The results of the bioinformatic molecular classification are concordant with the well-recognized roles of the tumor stroma in cancer biology (e.g., angiogenesis, immune response) as well as the roles of the parenchyma (i.e., malignant tumor cells) in tumorigenesis, as exemplified by the amplification of proliferative signals (e.g., EGF and Wnt signaling).