The Hedgehog Signaling Pathway in Cancer -- Rho GTPases and Cancer -- Developmental Biology of Fibroblasts and Neoplastic Disease -- The Extracellular Matrix During Normal Development and Neoplastic Growth -- Wilms’ Tumor: Starting Off the Kidney All Over Again? -- Testicular Teratomas: Back to Pluripotent Stem Cells -- Tumor Suppressors APC and VHL: Gatekeepers of the Intestine and Kidney -- Hormonal and Stromal Regulation of Normal and Neoplastic Prostatic Growth -- Neoplastic Growth Through the Developmental Stages of the Organism.In this book, tumour growth is perceived as a deviation from the normal development of the human organism. The molecular, cellular, and tissue determinants of different tumours are discussed showing that each is a different disease, often corresponding to a particular developmental stage. The natural history of several cancers illustrates how clinical incidence can be just the visible part of the iceberg, while the first changes at the tissue level sometimes occur several years before tumour growth becomes manifest. Several mechanisms are proposed to explain the distribution of cancers during the human life span and the decline of the incidence of cancers during human senescence.