Differentiation of nervous tissue, which occurs during CNS development, was first described in detail while investigating a model of rat brain through the use of a new biomarker known as alpha-fetoprotein, AFP. During this research, another model -mouse teratocarcinoma - enabled the description of the different steps of nervous tissue formation following distinct pathological ways of CNS development. Comparing these two processes gave rise to the following conclusions: a striking convergence exists between normal and neoplastic nervous tissue development and correlates with the presence of oncoproteins such as AFP and growth factor IGF-I. These interesting observations have oriented the pursuit of one goal: stopping the neoplastic CNS development conducing to the malignant tumor - glioblastoma. From this endeavor, stemmed an efficient anti-gene strategy targeting gene of growth factor IGF-I present in brain tumor development, inducing immune anti-tumor response and consequently, increasing the median survival of glioblastoma patients up to 2 years.